I've been using GrapheneOS on a 4A with TMobile as my daily driver for over a year and have had none of these issues. Never had an out-of-service notice from so

I've been using GrapheneOS on a 4A with TMobile as my daily driver for over a year and have had none of these issues. Never had an out-of-service notice from someone calling me, never had a call not initiate, and tethering works great. Maybe it's something to do with OpenGapps? I never installed it or microG, I'm perfectly happy with just Fdroid.