Phone Suddenly Drops Service unless on Wi-fi! -S22 Ultra

I know I am a bit late to this party, but I wanted to check in. Are you still having the same issues @Mross506?

Fireguy_6364 is right: the best way to know if the phone is the culprit is to see if the same thing happens on another phone right next to yours. Testing your sim card in a known working device is also helpful to see if your sim card is going bad. 

I would also double check your wifi calling setting. There is a calling preferences option that can cause a lot of issues if it is not set to Cellular Preferred. You also want to make sure that your software is completely up to date and your not using any third party task manager or battery saver apps. Those can shut down ANY functionality if it is using "too much" data or power. 

I hope this helps. Happy Holidays.