Good afternoon,
We recently installed some instrumentation in the field that makes use of the TRB140 for remote access and data downloading over ssh. The first setup was installed last Tuesday, but in the early morning hours of Saturday it lost connectivity and was no longer reachable over the RMS interface. We went back to the setup in the field, and upon connecting to the TRB140 locally we saw from the mobile network status page that the device kept trying to get a valid data connection without succeeding. The mobile network at the site itself is not at fault, as other devices had no trouble getting 4G connections there. We also checked the SIM card in a different device, which worked fine.
After a lot of puzzling we just decided to try a factory reset, and after this the TRB140 immediately successfully formed a 4G connection again. I don’t know what the cause of the connectivity problems was. As we have two more setups deployed at a much more remote location, I would like to understand how we might avoid the need for a factory reset with those setups, should they develop similar network connectivity issues.
I have system and kernel logs available from the device in question, both from when the connectivity issues were playing up and from when the issue was resolved after the factory reset. I can send these by email if desired. Ideally, after we manage to find the solution, I will post back here what it was 
Thanks in advance for your help!