Mikrotik DoH random resolving errors

[Eugene-Savenko]

If you're experiencing connectivity issues w/ AdGuard DNS-ver-HTTPS server and a Mikrotic device, please collect the logs and send them to support@adguard.com, or post in comments here.

1. Press the Webfig button in the top-right corner
2. Go to System > Logging > +
3. Set Topics for dns and Action for memory
4. Replicate the issue
5. Hit the Terminal button in the top right
6. Execute /log print file=log
7. Switch to Webfig
8. Download the log file from Files section

[Eugene-Savenko]

CRM ID: 711836

It works in general but starts throwing errors from time to time

More logs / screenshots

CRM ID: 711836

[Eugene-Savenko]

CRM ID: 690631

I have been using your Adguard DNS paid service for about 3 months; I found it excellent. I have presented an intermittency in their services and I have checked that it is in all the devices; I have routers with OPENWRT, Microtiks and Linux servers. [...] it is very random, sometimes once a week and other times in a single day. What it does show is that it is general, most of the time, all my devices lose the DNS service.

Screenshots / logs

CRM ID: 690631

[ivicask]

I have exactly the same issue on multiple locations and mostly mikrotik devices, but it's not so easy to get the log as it's random, I will try capture it when it happens

[ivicask]

I managed to capture few failures with detailed log.

13:49:09 dns,error DoH server connection error: Idle timeout - waiting data 
13:49:09 dns done query: #3128743 dns server failure 
13:49:09 dns,packet --- sending reply to 82.132.2.98:16582: 
13:49:09 dns,packet id:5668 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'server failure' 
13:49:09 dns,packet question: getim.ath.cx.:A:IN 
13:49:09 dns,packet --- sending reply to 82.132.2.98:62141: 
13:49:09 dns,packet id:dec9 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'server failure' 
13:49:09 dns,packet question: getim.ath.cx.:A:IN 
13:49:09 dns,packet --- sending reply to 82.132.2.98:10370: 
13:49:09 dns,packet id:7951 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'server failure' 
13:49:09 dns,packet question: getim.ath.cx.:A:IN 
13:49:09 dns,packet --- sending reply to 82.132.2.98:65470: 
13:49:09 dns,packet id:9198 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'server failure' 
13:49:09 dns,packet question: getim.ath.cx.:A:IN 
13:49:09 dns,packet --- sending reply to 82.132.2.98:56711: 
13:49:09 dns,packet id:7edc rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'server failure' 
13:49:09 dns,packet question: getim.ath.cx.:A:IN 
13:49:09 dns local query: #3128778 12e43f99.d.adguard-dns.com. A 
13:49:09 dns done query: #3128778 12e43f99.d.adguard-dns.com 94.140.14.49 
13:49:09 dns local query: #3128779 12e43f99.d.adguard-dns.com. AAAA 
13:49:09 dns done query: #3128779 12e43f99.d.adguard-dns.com 2a10:50c0::ded:ff 
13:49:09 dns done query: #3128733 beacons5.gvt2.com. 
13:49:09 dns,packet --- sending reply to 192.168.254.34:27846: 
13:49:09 dns,packet id:9729 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'no error' 
13:49:09 dns,packet question: beacons5.gvt2.com.:A:IN 
13:49:09 dns,packet answer: 
13:49:09 dns,packet <beacons5.gvt2.com.:A:500=0.0.0.0> 
13:49:09 dns,packet --- sending reply to 192.168.254.34:43973: 
13:49:09 dns,packet id:4e33 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'no error' 
13:49:09 dns,packet question: beacons5.gvt2.com.:A:IN 
13:49:09 dns,packet answer: 
13:49:09 dns,packet <beacons5.gvt2.com.:A:500=0.0.0.0> 
----------------------------------------------------------------------------------------------------------
13:49:14 dns,error DoH server connection error: SSL: internal error (6) 
13:49:14 dns done query: #3128755 dns server failure 
13:49:14 dns,packet --- sending reply to 192.168.255.200:35069: 
13:49:14 dns,packet id:a242 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'server failure' 
13:49:14 dns,packet question: presence.teams.microsoft.com.:A:IN 
13:49:14 dns local query: #3128802 12e43f99.d.adguard-dns.com. A 
13:49:14 dns done query: #3128802 12e43f99.d.adguard-dns.com 94.140.14.49 
13:49:14 dns local query: #3128803 12e43f99.d.adguard-dns.com. AAAA 
13:49:14 dns done query: #3128803 12e43f99.d.adguard-dns.com 2a10:50c0::ded:ff 
13:49:14 dns,packet --- got query from 192.168.254.37:5529: 
13:49:14 dns,packet id:3df4 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:14 dns,packet question: metrics2.data.hicloud.com.:A:IN 
13:49:14 dns,packet --- got query from 192.168.255.111:52429: 
13:49:14 dns,packet id:fa57 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:14 dns,packet question: configuration.ls.apple.com.:UNKNOWN (65):IN 
13:49:14 dns query from 192.168.255.111: #3128804 configuration.ls.apple.com. UNKNOWN (65) 
13:49:14 dns,packet --- got query from 192.168.255.111:58821: 
13:49:14 dns,packet id:597c rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:14 dns,packet question: configuration.ls.apple.com.:A:IN 
13:49:14 dns query from 192.168.255.111: #3128805 configuration.ls.apple.com. A 
13:49:14 dns,packet --- got query from 192.168.255.111:7882: 
13:49:14 dns,packet id:89e6 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:14 dns,packet question: gspe35-ssl.ls.apple.com.:UNKNOWN (65):IN 
13:49:14 dns query from 192.168.255.111: #3128806 gspe35-ssl.ls.apple.com. UNKNOWN (65) 
13:49:14 dns,packet --- got query from 192.168.255.111:13804: 
13:49:14 dns,packet id:5d22 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:14 dns,packet question: gspe35-ssl.ls.apple.com.:A:IN 
13:49:14 dns query from 192.168.255.111: #3128807 gspe35-ssl.ls.apple.com. A 
13:49:14 dns,packet --- got query from 192.168.255.111:32231: 
13:49:14 dns,packet id:2f41 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:14 dns,packet question: captive.apple.com.:UNKNOWN (65):IN 
13:49:14 dns query from 192.168.255.111: #3128808 captive.apple.com. UNKNOWN (65) 
13:49:14 dns,packet --- got query from 192.168.255.111:31716: 
13:49:14 dns,packet id:1cf4 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:14 dns,packet question: captive.apple.com.:A:IN 
13:49:14 dns query from 192.168.255.111: #3128809 captive.apple.com. A 
13:49:14 dns,packet --- got query from 192.168.255.111:12248: 
13:49:14 dns,packet id:f6db rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:14 dns,packet question: gsp85-ssl.ls.apple.com.:UNKNOWN (65):IN 
13:49:14 dns query from 192.168.255.111: #3128810 gsp85-ssl.ls.apple.com. UNKNOWN (65) 
13:49:14 dns,packet --- got query from 192.168.255.111:30912: 
13:49:14 dns,packet id:aa7c rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:14 dns,packet question: gsp85-ssl.ls.apple.com.:A:IN 
13:49:14 dns query from 192.168.255.111: #3128811 gsp85-ssl.ls.apple.com. A 
13:49:14 dns,packet --- got query from 82.132.2.98:53378: 
13:49:14 dns,packet id:e541 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:14 dns,packet question: youtube-ui.l.google.com.:A:IN 
13:49:14 dns query from 82.132.2.98: #3128812 youtube-ui.l.google.com. A 
13:49:14 dns done query: #3128812 youtube-ui.l.google.com. 172.217.168.206 
13:49:14 dns,packet --- sending reply to 82.132.2.98:53378: 
13:49:14 dns,packet id:e541 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'no error' 
13:49:14 dns,packet question: youtube-ui.l.google.com.:A:IN 
13:49:14 dns,packet answer: 
---------------------------------------------------------------------------------------------------
13:49:19 dns,error DoH server connection error: SSL: ssl: close notify received (6) 
13:49:19 dns done query: #3128764 dns server failure 
13:49:19 dns,packet --- sending reply to 192.168.255.49:54467: 
13:49:19 dns,packet id:9841 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'server failure' 
13:49:19 dns,packet question: FRA-efz.ms-acdc.office.com.:AAAA:IN 
13:49:19 dns local query: #3128866 12e43f99.d.adguard-dns.com. A 
13:49:19 dns done query: #3128866 12e43f99.d.adguard-dns.com 94.140.14.49 
13:49:19 dns local query: #3128867 12e43f99.d.adguard-dns.com. AAAA 
13:49:19 dns done query: #3128867 12e43f99.d.adguard-dns.com 2a10:50c0::ded:ff 
13:49:19 dns,packet --- got query from 192.168.255.130:22262: 
13:49:19 dns,packet id:9c21 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:19 dns,packet question: mesu.apple.com.:UNKNOWN (65):IN 
13:49:19 dns,packet --- got query from 192.168.255.130:26360: 
13:49:19 dns,packet id:d43 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:19 dns,packet question: mesu.apple.com.:A:IN 
13:49:19 dns,packet --- got query from 192.168.255.130:13032: 
13:49:19 dns,packet id:54f5 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:19 dns,packet question: basejumper.apple.com.:UNKNOWN (65):IN 
13:49:19 dns query from 192.168.255.130: #3128868 basejumper.apple.com. UNKNOWN (65) 
13:49:19 dns,packet --- got query from 192.168.255.130:18122: 
13:49:19 dns,packet id:c9f8 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:19 dns,packet question: basejumper.apple.com.:A:IN 
13:49:19 dns query from 192.168.255.130: #3128869 basejumper.apple.com. A 
13:49:19 dns,packet --- got query from 192.168.254.34:5367: 
13:49:19 dns,packet id:c50 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:19 dns,packet question: beacons5.gvt3.com.:A:IN 
13:49:19 dns,packet --- got query from 82.132.2.98:37596: 
13:49:19 dns,packet id:832 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:19 dns,packet question: www.gstatic.com.:UNKNOWN (65):IN 
13:49:19 dns,packet --- got query from 192.168.255.130:52462: 
13:49:19 dns,packet id:2dec rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:49:19 dns,packet question: time.apple.com.:A:IN 
13:49:19 dns query from 192.168.255.130: #3128870 time.apple.com. A 
13:49:19 dns done query: #3128870 time.apple.com. 17.253.108.125 
13:49:19 dns,packet --- sending reply to 192.168.255.130:52462: 
13:49:19 dns,packet id:2dec rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'no error' 
13:49:19 dns,packet question: time.apple.com.:A:IN 
13:49:19 dns,packet answer: 
13:49:19 dns,packet <time.apple.com.:CNAME:6846=time.g.aaplimg.com.> 
13:49:19 dns,packet <time.g.aaplimg.com.:A:546=17.253.108.125> 
13:49:19 dns,packet <time.g.aaplimg.com.:A:546=17.253.14.253> 
---------------------------------------------------------------------------------------------
13:49:36 dns,error DoH server connection error: Idle timeout - waiting data 
13:49:36 dns done query: #3128797 dns server failure 
13:49:36 dns,packet --- sending reply to 82.132.2.98:41090: 
13:49:36 dns,packet id:7708 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'server failure' 
13:49:36 dns,packet question: i.ytimg.com.:UNKNOWN (65):IN 
13:49:36 dns,packet --- sending reply to 82.132.2.98:37507: 
13:49:36 dns,packet id:fa2b rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'server failure' 
13:49:36 dns,packet question: i.ytimg.com.:UNKNOWN (65):IN 
13:49:36 dns,packet --- sending reply to 82.132.2.98:24277: 
13:49:36 dns,packet id:d01d rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'server failure' 
13:49:36 dns,packet question: i.ytimg.com.:UNKNOWN (65):IN 
13:49:36 dns,packet --- sending reply to 82.132.2.98:54981: 
13:49:36 dns,packet id:2b6b rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'server failure' 
13:49:36 dns,packet question: i.ytimg.com.:UNKNOWN (65):IN 
13:49:36 dns,packet --- sending reply to 82.132.2.98:14284: 
13:49:36 dns,packet id:43c3 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'server failure' 
13:49:36 dns,packet question: i.ytimg.com.:UNKNOWN (65):IN 
13:49:36 dns local query: #3128978 12e43f99.d.adguard-dns.com. A 
13:49:36 dns done query: #3128978 12e43f99.d.adguard-dns.com 94.140.14.49 
13:49:36 dns local query: #3128979 12e43f99.d.adguard-dns.com. AAAA 
13:49:36 dns done query: #3128979 12e43f99.d.adguard-dns.com 2a10:50c0::ded:ff 
13:49:36 dns done query: #3128822 dns name exists, but no appropriate record 
13:49:36 dns,packet --- sending reply to 192.168.255.111:11461: 
13:49:36 dns,packet id:5095 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'no error' 
13:49:36 dns,packet question: pds-init.ess.apple.com.:UNKNOWN (65):IN 
13:49:36 dns,packet answer: 
13:49:36 dns,packet <pds-init.ess.apple.com.:CNAME:164=pds-init.ess.apple.com.edgesuite.net.> 
13:49:36 dns,packet <pds-init.ess.apple.com.edgesuite.net.:CNAME:164=a1864.gi3.akamai.net.> 
13:49:36 dns,packet authority: 
13:49:36 dns,packet <gi3.akamai.net.:SOA:164=mname:n0gi3.akamai.net. rname:hostmaster.akamai.com. serial:1678193239 refresh:1000 retry:1000 expire:1000 min:1800> 
13:49:36 dns,packet --- sending reply to 192.168.255.130:58346: 
13:49:36 dns,packet id:f61b rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'no error' 
13:49:36 dns,packet question: pds-init.ess.apple.com.:UNKNOWN (65):IN 
13:49:36 dns,packet answer: 
13:49:36 dns,packet <pds-init.ess.apple.com.:CNAME:164=pds-init.ess.apple.com.edgesuite.net.> 
13:49:36 dns,packet <pds-init.ess.apple.com.edgesuite.net.:CNAME:164=a1864.gi3.akamai.net.> 
13:49:36 dns,packet authority: 
--------------------------------------------------------------------------------------------------------------
13:50:03 dns,error DoH server connection error: SSL: internal error (6) 
13:50:03 dns done query: #3128869 dns server failure 
13:50:03 dns,packet --- sending reply to 192.168.255.130:18122: 
13:50:03 dns,packet id:c9f8 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'server failure' 
13:50:03 dns,packet question: basejumper.apple.com.:A:IN 
13:50:03 dns local query: #3129137 12e43f99.d.adguard-dns.com. A 
13:50:03 dns done query: #3129137 12e43f99.d.adguard-dns.com 94.140.14.49 
13:50:03 dns local query: #3129138 12e43f99.d.adguard-dns.com. AAAA 
13:50:03 dns done query: #3129138 12e43f99.d.adguard-dns.com 2a10:50c0::ded:ff 
13:50:03 dns,packet --- got query from 192.168.254.2:57560: 
13:50:03 dns,packet id:75ba rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:50:03 dns,packet question: mail.google.com.:A:IN 
13:50:03 dns,packet --- got query from 82.132.2.98:42150: 
13:50:03 dns,packet id:e5b9 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:50:03 dns,packet question: inbox.google.com.:A:IN 
13:50:03 dns,packet --- got query from 82.132.2.98:23468: 
13:50:03 dns,packet id:cb43 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:50:03 dns,packet question: outlook.office365.com.:UNKNOWN (65):IN 
13:50:03 dns,packet --- got query from 82.132.2.98:25520: 
13:50:03 dns,packet id:89c1 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:50:03 dns,packet question: outlook.office365.com.:A:IN 
13:50:03 dns,packet --- got query from 192.168.255.80:14555: 
13:50:03 dns,packet id:6c3d rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:50:03 dns,packet question: downloads.upd.kaspersky.com.:AAAA:IN 
13:50:03 dns,packet --- got query from 192.168.255.80:14811: 
13:50:03 dns,packet id:e14a rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:50:03 dns,packet question: downloads.upd.kaspersky.com.:A:IN 
13:50:03 dns,packet --- got query from 192.168.255.205:46312: 
13:50:03 dns,packet id:5f13 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:50:03 dns,packet question: configuration.apple.com.:UNKNOWN (65):IN 
13:50:03 dns query from 192.168.255.205: #3129139 configuration.apple.com. UNKNOWN (65) 
13:50:03 dns,packet --- got query from 192.168.255.205:208: 
13:50:03 dns,packet id:e3aa rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:50:03 dns,packet question: configuration.apple.com.:A:IN 
13:50:03 dns query from 192.168.255.205: #3129140 configuration.apple.com. A 
13:50:03 dns,packet --- got query from 192.168.255.205:48577: 
13:50:03 dns,packet id:ef4 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:50:03 dns,packet question: time.g.aaplimg.com.:A:IN 
13:50:03 dns query from 192.168.255.205: #3129141 time.g.aaplimg.com. A 
13:50:03 dns done query: #3129141 time.g.aaplimg.com. 17.253.14.123 
13:50:03 dns,packet --- sending reply to 192.168.255.205:48577: 
13:50:03 dns,packet id:ef4 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'no error' 
13:50:03 dns,packet question: time.g.aaplimg.com.:A:IN 
13:50:03 dns,packet answer: 
-----------------------------------------------------------------------------------------------
13:56:00 dns,error DoH server connection error: SSL: internal error (6) 
13:56:00 dns done query: #3133194 dns server failure 
13:56:00 dns,packet --- sending reply to 192.168.255.49:17643: 
13:56:00 dns,packet id:31f1 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'server failure' 
13:56:00 dns,packet question: signaler-pa.clients6.google.com.:AAAA:IN 
13:56:00 dns local query: #3133238 12e43f99.d.adguard-dns.com. A 
13:56:00 dns done query: #3133238 12e43f99.d.adguard-dns.com 94.140.14.49 
13:56:00 dns local query: #3133239 12e43f99.d.adguard-dns.com. AAAA 
13:56:00 dns done query: #3133239 12e43f99.d.adguard-dns.com 2a10:50c0::ded:ff 
13:56:00 dns,packet --- got query from 192.168.255.104:51163: 
13:56:00 dns,packet id:38e9 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:56:00 dns,packet question: gateway.icloud.com.:A:IN 
13:56:00 dns query from 192.168.255.104: #3133240 gateway.icloud.com. A 
13:56:00 dns done query: #3133240 gateway.icloud.com. 17.248.145.134 
13:56:00 dns,packet --- sending reply to 192.168.255.104:51163: 
13:56:00 dns,packet id:38e9 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'no error' 
13:56:00 dns,packet question: gateway.icloud.com.:A:IN 
13:56:00 dns,packet answer: 
13:56:00 dns,packet <gateway.icloud.com.:CNAME:43158=gateway.fe.apple-dns.net.> 
13:56:00 dns,packet <gateway.fe.apple-dns.net.:A:45=17.248.145.134> 
13:56:00 dns,packet <gateway.fe.apple-dns.net.:A:45=17.248.145.205> 
13:56:00 dns,packet <gateway.fe.apple-dns.net.:A:45=17.248.145.104> 
13:56:00 dns,packet <gateway.fe.apple-dns.net.:A:45=17.248.145.79> 
13:56:00 dns,packet <gateway.fe.apple-dns.net.:A:45=17.248.145.141> 
13:56:00 dns,packet <gateway.fe.apple-dns.net.:A:45=17.248.248.83> 
13:56:00 dns,packet <gateway.fe.apple-dns.net.:A:45=17.248.248.36> 
13:56:00 dns,packet <gateway.fe.apple-dns.net.:A:45=17.248.248.53> 
13:56:00 dns,packet --- got query from 82.132.2.98:51103: 
13:56:00 dns,packet id:f409 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:56:00 dns,packet question: go.microsoft.com.edgekey.net.:A:IN 
13:56:01 dns,packet --- got query from 82.132.2.98:15551: 
13:56:01 dns,packet id:bd25 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:56:01 dns,packet question: eu-mobile.events.data.microsoft.com.:A:IN 
13:56:01 dns query from 82.132.2.98: #3133241 eu-mobile.events.data.microsoft.com. A 
13:56:01 dns,packet --- got query from 192.168.255.157:19691: 
13:56:01 dns,packet id:5592 rd:1 tc:0 aa:0 qr:0 ra:0 QUERY 'no error' 
13:56:01 dns,packet question: checkappexec.microsoft.com.:A:IN 
13:56:01 dns query from 192.168.255.157: #3133242 checkappexec.microsoft.com. A 
13:56:01 dns done query: #3133242 checkappexec.microsoft.com. 20.73.130.64 
13:56:01 dns,packet --- sending reply to 192.168.255.157:19691: 
13:56:01 dns,packet id:5592 rd:1 tc:0 aa:0 qr:1 ra:1 QUERY 'no error' 
13:56:01 dns,packet question: checkappexec.microsoft.com.:A:IN 
13:56:01 dns,packet answer: 

[mrkopl]

Not only adguard dns but other dns also have the same problem on MikroTik

There have been many complaints on the internet.

For that some people prefer to use/add raspberry-pi or docker.

[ivicask]

If its problem with mikrotik why DNS stops same time on my mobile phone (s23 ultra) i entered adguard as system dns and im over my mobile connection. I see errors on multiple locations SAME time, all locations looses connection to adguard servers including my phone, leaving me and users without net for 2-3 minutes.

[vktr2b]

Also experiencing the issue with NextDNS/Mikrotik, i was actually looking to replace NextDNS with AdguardDNS as i thought it's a NextDNS issue but after some testing different configs and DNS providers it's on Mikrotik.
I've made posts both on Mikrotik & NextDNS forum but without any reply's:

https://forum.mikrotik.com/viewtopic.php?p=1010679#p1010679

https://help.nextdns.io/t/y4h9mr2/doh-server-connection-error-host-is-unreachable