I am having difficulties with the 1st generation kit. Occasionally, it does connect to ATT LTE, but on most power-ups it does not. Looking at the output in cases when it fails I can identify two typical scenarios:
1) the modem initialization failure - infinitely repeating 0-60 count (Modem initializing... will take up to 60 seconds) and
2) infinitely failing registration [AT+CREG?+CREG: 2,0,0136,003AF009,7OK]
I understand that failure #2 is more difficult to fix because it depends not only on the kit but also on local towers, reception etc. although my cell phone report excellent reception and LTE. So I'd like to start troubleshooting with issue #1 - failure to initialize the modem. That should be something perfectly doable with software irrespective of external factors. Please advise.