[Q] how come suddenly it can't keep a signal after switching sims/services(tmob2aio)

yeah, first thing i accomplished successfully tho not without a lot of wiping an rewiping and installing and reinstalling stuff, was unlocking the phone, then i put in the aio and it did it's thing on it's own and connected wonderfully. first time trying to go back to tmob, it started this misconnection issue. it's basically intermittent closer to non operational, tho i did get a random text tonight from a friend i was unable to respond to, because im like kinda connected for a sec, sometimes i'll see the opposing 4g arrows working in the notification area, but not long enough to get info set in the apn settings, you know where i'm talking about. half of those settings work only when you have a signal, for ex. i do the manual part correctly, hit the save apn button ... nothing saves, nothing happens better after that.

i bet you i need to update that radio huh? just tried to flash a newer rom and it said no because my radio was too old. i could have sworn my stock rom, which is supposed to be the latest... which maybe was old right? its in the threads here, first stock you'll find. probably that rom was cool with the uvle1... confusing stuff. okay, til someone answers otherwise i'm just gonna keep trying to update this radio. i guess it is only good now for unlocking...

okay, so i just flashed jedi mind trick which updated the radio, but the stock rom didn't. so does that mean that some roms will not touch the radio while others will? and what was wrong with the radio before? was it made to work only for the associated older versions of android?