I switched from Verizon with the same phone I was using there. After porting my number over and getting service activated with the new SIM card, everything is working except voice calls often don't work - incoming and outgoing. If I'm unable to make a call, I can restart the phone and it will work fine, until maybe the next time I want to make a call. I've played with Android settings per info I've found here, but it's the same. Tried wi-fi calling on and off.
It also seems like I may have a T-Mobile SIM but I want a Verizon SIM. Much better service in my area. I see APN T-Mobile LTE.
I always get "SIM card is not from Verizon Wireless" after restarting the phone.
OnePlus 8 5G UW