Mobile Operator *suddenly* No Longer Found with at+cops=?

Greetings All! I’m pretty new to the do-it-yourself Cellular Internet stuff so please forgive me…
I have a Quectel RM520N-GL inside of an OpenWRT Machine, with the intended use being the Primary Internet Uplink for my home (as Fixed Line options are diabolical…)

I’ve been tinkering with this setup for the last 3 days, seeing whats what, how it all works, etc, and managed to get it figured out and ironed out most the issues.
However, for whatever reason, it now seems my Network Operator (EE UK) has just ceased to exist for the Modem
at+cops=? No Longer returns EE as an Operator, and only returns O2, and rarely 3(Three), both of which, I cannot use.

Manually attempting at+cops=1,2,"23430" hangs for a while, before returning CME Error 30 (no network service).
at+qeng="servingcell" Returns +QENG: "servingcell","LIMSRV","WCDMA",234,10,5473,26B5D1A,3025,112,145,-96,-11,-,-,-,-,-

SIM Card is completely fine, as all relevant AT commands return what they should, the Operator (EE) is not down, as the SIM works fine in another 5G Router I have, same goes for the 2 Antennas I am using.

The only settings I have really messed around with regarding AT Commands are at+qnwlock, at+qnwprefcfg for Cell Locking & Band Locking.
I have scoured the internet and forums alike looking for a solution to this issue to no avail. The problem occurred seemingly out of nowhere, one moment I was trying to find the best cells and bands to lock to, annnnd the next I suddenly have No Operator…
Note; I have reset all of the settings I was playing around with, ran the appropriate AT commands to clear settings, etc.

Can anyone here shed some light on this problem? I’ve just about pulled all of my hair out…

Thankyou

Dear @TheGooseMan
Please check the following AT commands:
AT+QCSQ
AT+COPS?
AT+QENG=“servingcell”
AT+QSCAN
AT+QNWPREFCFG=“mode_pref”
AT+QMBNCFG=“list”