Sorry if this has been answered before, did read OP, and quite a lot of pages in between, including using search.
So my HTC One m8 was originally purchased from Three (UK) with CID number H3G__001. Some time after I S-OFFd and changed it to superCID, then ran some RUU to get to .401 software. Currently running latest Lollisense .401.10
Anyway having problem with phone signal, constantly poor (less than 2 bars). Suspect its probably helping my battery to drain quicker. Anyway question is, I probably need to flash a H3G radio, right? Can I take the latest H3G firmware, take out the radio.img and just flash it using rebootRUU?
To confirm I am S-OFF. Thanks.
Please check your Os in bootloader.
Did you wipe your phone before flash Rom?