Alliance Apps OpenDTU didn't communicate with HMS-1600-4T

[Schilli1-1984]

Hey guys, i've been working with an old ahoyDTU with my HM-1500. I bought a second Inverter, HMS-1600-4T, the old ahoyDTU couldn't handle it because of the missing antenna (ony NRF24 module). Therefore, i bought an Alliance Apps OpenDTU with both connection modules.
Unfortunately, the HMS inverter is not found. It is working and producing, LED is flashing green, distance to DTU approx. 4 Meter.
I was able to find my old HM-1500 with a distance of approx. 15m. i played around with all allowed frequences, transmission power etc., but i have only 2% RX success, 29% nothing received and 69% partial received.
Even if i put the DTU directly next to the Inverter, nothing is received.
Has anyone any idea, which things i have to do / configurate etc.? Firmware is already 25.9.11
Thanks for your support, i'm frustrated that it didn't work as expected :(
Thanks
Michael

[ms49434]

Please check that you have the right antenna properly connected to the CMT2300a module. The connector is very tiny and it could be that the pin is broken or isn't connected properly. Just disconnect and reconnect the plug.

[Schilli1-1984]

I bought it ready assembled. I haven't opened it yet, in the App the Status of CMT2300A is configured and the Chip Status is connected. Would that be also the case if the module is not properly connected?