@Lebar After this message, a member of 1st level support (the programmer) contacted me by e-mail. The problem is still not solved, but we are working on it. That is very pleasing. I am very impressed.

@David-TP I have not noticed any change in the LED lights. But I think it's very unlikely, as I have stable 5G here. My provider is Deutsche Telekom.

I have a Deco BE65-5G. The mobile Internet is stable at 200-300 mbps, ping 12-13. Connection via cable works very well, I can even play fps games. The connection is actually also good via WiFi,...