AT&T and Quectel E25 Modem

I have a Quectel E25 Modem inside of a WE826-T2. It has been working with my AT&T SIM card for about 8 months and now it just quite working. I can take the SIM card out and put it into my iPad and everything works great. I can even put my SIM card out of my iPhone into the WE826-T2 and everything works fine. I am just not sure why the original SIM card stopped working in the WE826-T2 with the Quectel Modem. I am assuming that there needs to be some AT Commands that I need to do to get this SIM card working again.

Any help would be so greatly appreciated!!

Hi
I think the problem may be on the apn, please set your apn correctly; have you inserted this card into another ec25 module to see if the module is working properly?
Best wishes