I am no longer getting calls ringing on the Teams app on both of my cellphones, it did work at one point in time. I have an iPhone 8 (ios 14.3) and an LG V60 (Android 10).
I searched for a fix on here and saw that others were able to log out of the app and back in and it fixed the synchronization for them. I tried this, even deleted the apps and reinstalled them on both phones, still not working for me.
I checked on the desktop Teams app and it is not forwarding to voicemail and I don't have an option to set it to forward to a mobile number, only forward to VM.