MAX BR1 ENT CAT12 Resetting Frequently

I just purchased a MAX BR1 ENT CAT12, and transferred over a SIM card that I had in a MAX BR1 Mini. I’ve been using an AT&T SIM since March that’s been working very well up until switching devices last week. Now, it seems to be resetting consistently throughout the day and night. Signal is strong (consistently full bars), so it’s not an issue with connection strength.

Wondering if it has to do with the SIM itself. I’ve heard about this becoming more prevalent with other third party SIM providers, which has me concerned about termination of service.