N971N - Limited Service after firmware upgrade

[zainmerchant]

I have a Galaxy Note 10 N971N which was running a custom firmware earlier and my T-Mobile sim card was working perfectly fine. I recently factory reset my phone and upgraded to Android 12, latest firmware available. Ever since the upgrade, my phone is showing Limited Service and the SIM card is not working at all. I tried AT&T as well but it keeps giving the same error.

Already went to T-Mobile's store, they changed my SIM card, reset network settings but nothing seems to work. How can I fix this?

Thanks in advance.

 

[blackhawk]

Factory reset after loading 12?
Make sure 4G VoLTE is enabled, etc check dial code phone settings. *#*#4636#*#*

 

[zainmerchant]

Factory reset after loading 12?
Make sure 4G VoLTE is enabled, etc check dial code phone settings. *#*#4636#*#*

View attachment 5649171

I tried factory resetting and that didn't do anything either. Also ever since I've flashed this firmware, I keep getting some message in Korean every time I restart and I think it says that my bootloader is unlocked or something like that.

 

[blackhawk]

I tried factory resetting and that didn't do anything either. Also ever since I've flashed this firmware, I keep getting some message in Korean every time I restart and I think it says that my bootloader is unlocked or something like that.

The bootloader should be locked unless you unlocked it. You should be able to roll back to 11 unless it upgraded the bootloader. So far nobody's reported this on Samsung with 12.

 

[jamesrrred]

Any custom ROMs working for this device?