How to undo the Verizon Installation.

[kevelev]

So I bought a used Samsung Galaxy S9+ (Model: SM-G965U) that was factory unlocked for both GSM and CDMA use. It came with Android 8. I wanted to try out Tracfone as the carrier, so I got a SIM card from Tracfone that used Verizon's CDMA network. After configuring the SIM card and rebooting my phone, the phone started installing Verizon software, and apps, and now behaves like a Verizon phone. I now switched over to Mint Mobile, which I believe uses the T-Mobile network, but it still shows Verizon when the phone boots, and I can't get rid of that or the Verizon apps. The "Service provider SW ver." also still shows "VZW/XAA/SPR", so I'm wondering how to get rid of the "Verizonness" of the phone and get it back to normal. What I really want to do is allow the phone to be updated to Android 9.0. Is there any way to do this?

 

[kevelev]

Also, when I restart the phone, there is a warning that says "SIM card is not from Verizon Wireless". Keep in mind this is an unlocked phone, so I don't want it to think it belongs to Verizon anymore.

 

[ocnbrze]

not sure but sounds like you need to take it into your carrier that you have now to get it fixed......not really sure what you can do on your end.

 

[kevelev]

If I do a factory reset, would that take care of the issue?

 

[svim]

If I do a factory reset, would that take care of the issue?

Perhaps, but you might not need to. If you actually saw those Verizon apps getting installed after you installed that Verizon SIM card, those apps are probably installed as typical user-level apps. Have you tried Uninstalling them?
Go into your Settings >> Apps menu, find and open any Verizon-centric apps in the list, tap on 'Force stop' and find the 'Clear data' for each,and then tap on 'Uninstall'.
Be sure to use 'Clear data', that wipes the app's cache but most importantly any settings/configuration files for that app.

Edit:
Try restarting your phone into its Safe Mode. When running in Safe Mode it's just the Android operating system, with no third-party apps getting pre-loaded. If those Verizon apps don't load up in Safe Mode at least you know they are user-level apps and not system-level apps.
https://www.hardreset.info/devices/samsung/samsung-galaxy-s9-plus/safe-mode/
Another thing to try before a Factory Reset is to try wiping the system cache partition. You need to restart your phone into its Recovery Mode to access the option to do it though. Follow these directions to get into Recovery:
https://www.hardreset.info/devices/samsung/samsung-galaxy-s9-plus/recovery-mode/
and then select the 'wipe cache partition' option. Reboot and see if the same problem is occurring.

If you do opt to do a Factory Reset, don't forget to back up all your data first.