LG Lucid: Not receiving text messages

Hey! I'm on here for my mom's phone. Which, of course you can tell by the forum, is the LG Lucid. Okay so basically it just stopped receiving text messages. Like as far as i can tell, for no reason. Is there anyone out there who knows what its doing or how to fix it I'd love to know!

I do work for best buy mobile and I'd love as technical of an explanation as possible so i can understand what happening if a customer comes in with the same problem.

So far I have tried updating everything i could to do with the network and even updated the PRL just to see if that fixed it. I also power cycled and a soft reset. I did not try the hard reset, because its just a pain. The phone is not rooted or anything special either