Verizon Note 4 - refusing to use (non-verizon) SIM card.

[manhattan212]

I purchased a Verizon Note 4 N910V.05 off eBay.
When I got it, it had a custom ROM (didn't mention Verizon anywhere except for the logo on the back) and it worked fine with whatever SIM card I threw at it. At that time it was running Android 4.X

With time my phone started to get laggy and buggy, so I decided to reset to factory, and while I was at it, I decided to update to the most current official android version available to the phone: Android 6.0.1

Now, the phone won't use SIM cards I put it in it. It demands a Verizon one.
I read somewhere that I could just put one in, remove it, and then the phone should work fine with different carrier's SIM card. I tried but that didn't resolve my issue.

I also tried downgrading to previous android versions, hoping to root or do something -but no joy.

The phone shows the 4G notification and it receives (but not send) text messages -it doesn't send or receive phone calls -or data. I know the hardware is capable, because up until I updated to Android 6.0.1, it was working.

Does anyone know of a tried and true solution to getting this phone working again? Should I be trying to install a different ROM that's not for Verizon? Should I be trying to do something else? I'd really like to get my phone working again.

Any and all suggestions are appreciated.

 

[Rukbat]

Should I be trying to install a different ROM that's not for Verizon?

ABSOLUTELY NOT! If you flash a GSM ROM, you could hard-brick the phone.

See Device Unlocking Policy | Verizon Wireless. There's a phone number there that you can call to get unlock instructions.