I have a Sonim XP5s.
The Device allows me to call, send and recive text messages.
However is does not allow calls made to me.
I have checked all settings and it has not resolved the issue. After turning them on then off.
It still can't recieve calls...
Have you called customer service at 800-922-0204 for support? Maybe they can open a ticket and escalate to technical support.
We always want your device to be up and running at all times. We can help here. What do you hear when you attempt to make a call? When did this issue start?