Question [Q] Rooted & unlocked i337 asking to insert sim

Hoping someone can help me figure this out.Created a new topic because it seems a bit different from the other "no sim" topic.

I have an i337 on MF3 that was rooted and unlocked using jortex's method and chainfire's region unlock.

I used it on Tmobile's network for about 16hrs without problem, then it suddenly started showing emergency calls only and asking to insert sim. I've place the tmobile sim in another phone and it worked fine, also put an unactivated AT&T sim in the S4 and it sees it. The phone is still booting up with the samsung custom screen. Any ideas on how to fix?

Thanks in advance.