If you don't know whether the stock rom which came pre-installed was for your region or not the only advice i can give here is to use XperiFirm + newflasher or flashtool and start from the beginning. Maybe flashing only the modem partition is also enough. You could check if the referenced mbn file is in your modem partition.Hello dtrunk90,
I bought my phone in amazon spain and came from stock firmware. Unfortunately i don't know if was an european rom or not but I never had problems with coverage.
Regarding Option1/Option2, I used option 2 (magisk+safetyNet) and I can use my bank app but I only have problems with google wallet. I will try to update to the next LOS but is only this app.
Could you please let me know too where can I find the correct modem config version for spain?
It's not just magisk+universal safetynet fix. you also have to set a fingerprint manually with another module and props command. and you have to do some other stuff like deny listing apps. if you've ran wallet before passing safetynet also deleting app data might be a good idea.