Cannot connect to wifi (2.4 / 5GHz)

MartinD

My Repetier server on pi4 wont connect to wifi, pi4 with raspbian software can connect to it, however repetier server cannot, I tried everything even manual wifi config, I setup the wifi, pressing connect button, but after a while it goes back to wifi networks with text "unconnected", sometimes the message "Oops! I lost my connection to the server. Trying to reconnect" appears. That is wrong, I think, to what server it try to connect?
I have set "never enable AP".
I need help with this, because repetier server is worthless for me without wifi...

MartinD

I am on latest repetier server version, and trying to connect to wifi router in direct visibility 2m away.

Repetier

Did you set region correctly? Otherwise router might be using a band not allowed in default region like channer 12/13 in germany.

Where do you see the oops message? On pi display or remote, because this would mean there was at least a connection which just breaks.

We use the same linux network management - on current versions Network Manager. When you copy file /boot/firmware/ManualWifi.conf.sample to /boot/firmware/ManualWifi.conf you bypass our management to 100%. Then the config is copied to network manager as config.