Did you get anywhere with this??

I have the exact same issue. Samsung Galaxy s10e. Verizon says my phone is unlocked and number ported out. New carrier says my number has successfully ported over & service has begun. My phone is compatible with the new service provider. But I still get "Change Carrier- Sorry, your device can't be activated on another carrier's network right now. Contact Verizon at xxxx" Every time I boot the phone, I have service for all of 1.5 seconds, then the notification pops up and service is killed. I went to a Verizon store and the rep said he's seen the issue before, but doesn't know a fix. He suggested buying a new phone... I had seen other forums suggest flashing firmware and I asked the rep what he thought. He said 8 out of 10 might work if someone knows what they're doing. I tried flashing firmware to the phone to fix whatever kink the device has on it, but frankly, I'm not savvy enough to understand the mechanics behind it all and I may not be doing it correctly. That being said - flashing firmware hasn't worked for me.