iOS16 upgrade to iPhone SE 2020 (2nd gen) caused T-Mobile to now only show “SOS only”

Hello … has anyone else had cellular connectivity problems following the iOS 16 upgrade? After upgrading my iPhone SE 2nd-gen (2020) to iOS 16 last night, my mobile connection went from 4 bars @ T-Mobile to “SOS only”, and neither my nano-SIM nor my wife’s can get a valid connection (even after rebooting and/or also reset network settings). In fact, if I power-up with wi-fi only, inserting the SIM after logging in with passcode briefly flashes “No SIM Available”, then a “Searching” message in the upper-left corner, 4 bars draw then wipe, and then the cellular connectivity is replaced with “SOS only”, and NEVER changes from “SOS only” regardless of ejecting nor re-inserting while powered up. This has me believing that T-Mobile wasn’t expecting iPhone SE2’s to be running iOS 16, and so my device is “blocked” until it gets a cold reboot before re-evaluating … but TMo’s entry-level techs have no way to validate my IMEI, SIM, or model & iOS combo to see the network currently believes I’m running a “pirate build” or something, so now I have to turn to Apple and/or hope others with iPhone SE2 are also wishing they never upgraded.🤣

Yes, I know I can downgrade to 15.7, for the next 7 days or so, to get covered for recent 0-day vulns, but that wouldn’t be sporting nor fun.😜