wget hangs with proxy

[fred-cm]

Hello

I'm using the static wget on centos 7 - CentOS Linux release 7.2.1511 (Core)

With env variables set, http_proxy and https_proxy, the wget hangs :

# wget -v --header 'Content-Type: application/json' --post-data=' {"text": "hi, just a \nnew test."}' https://mattermost......
--2020-07-22 14:00:01--  https://mattermost.....
Resolving proxy-... 10.75.125.202
Connecting to proxy-...|10.75.125.202|:3128..

-- hangs --

strace gives :

socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 4
connect(4, {sa_family=AF_INET, sin_port=htons(3128), sin_addr=inet_addr("10.75.125.202")}, 16) = 0
futex(0x898a88, FUTEX_WAIT_BITSET_PRIVATE|FUTEX_CLOCK_REALTIME, 3, NULL, ffffffff

Can you see why ?

Thanks a lot
Regards