Sometimes, and unpredictably, incoming POTS calls will not cause the phone to ring.
Incoming VoIP calls cause the phone to ring ok.
If I reboot the router, calls will cause the phone to ring again, for a while.

I have tried the command "voip dsp relaydbounce off", but it doesn't help - the console reports this as no longer supported anyway.

The router is on the latest firmware.
Does anyone have any ideas before I raise it (again) with Draytek support?

Thanks