Anyone else having Verizon issues? In the same (maybe only similar?) situation. First, my SIM is recognized by the phone as a sprint SIM. Fair. It was about 5 years old, and frankly I don't know what has changed over the years. I loaded it back into my note 8 and headed up to the Verizon store to get a newer one. Same issue.
Whats happening for me, as a result, is constant tower jumping, my Cosmo telling me I'm roaming while also telling me I'm on a Verizon tower (some times). When I can connect to any tower, it's at best 50/50 if I'll have data, texting, and calling.
I suspect phone-side, the APNs need tweaking. However, being Verizon, the SIM card locks that out. To the point that APNs aren't in the settings. I rooted the phone, in hopes of finding some way around this. Followed several tutorials online to get APN settings back, but Magisk, being a systemless root, no methods stick.
I've also started using the built-in Engineer Mode - the good one - to try tweaking antenna /receiver settings. Able to jump through different network types and world modes. It can help at times, for short periods, but I suspect the temporary resolution is due more to the power-cycling of the receiver that is involved with some of these setting changes.
All said, I love this phone. Just looking forward to getting it to work right with Verizon.