How to tell if AT&T is blocking the IMEI?

Everything Else Wireless Carrier Troubleshooting
1

I have only been using T-Mobile so far. But now I’m in a location where T-Mobile’s service is unreliable. So I went to town and picked up an AT&T prepaid data-only SIM for mobile routers & tablets. When I put the SIM card into my Peplink MAX BR1 Pro 5G, it keeps showing “Connecting…” forever in the dashboard, it does recognize the IMSI and ICCID though. I tried putting the SIM card into a laptop with WWAN/LTE support and Windows 11 keeps showing “No service” but recognizes it as an AT&T SIM card. I also tried putting the SIM card into an Andorid phone where it showed the status “No connection” but given that this plan is specifically only for mobile routers and tablets I kind of expected it not to work in the phone.

  • Is there any way to tell whether AT&T it blocking the IMEI of the Peplink router, or whether there is just no AT&T coverage in my area?
  • Did others had trouble getting AT&T data only SIM cards to work with their Peplink router, and how did you resolve the issue?
2

I called AT&T support today, and they were able to activate my service for use with my Peplink router. The call went more straightforward than expected but according to what they told me at the AT&T store when I picked up the SIM card should not have been necessary nevertheless.

Still kinda curious though if it’s possible to tell the difference between carrier blocking your device and no carrier coverage.