Sorry, first time here... did answer instead of comment... Trying to correct...
All I can say is that I go through a checklist when setting up routers and enabling auto reboot (just enabling the default rule - 5 min pings to 22.214.171.124) was ticked, yet when I checked it was disabled. If I made a mistake, I take full responsibility here.
I also attempted to use SMS reboot, however, there was no response, nor are any messages showing up in the SMS inbox.
Unfortunately, I did a firmware upgrade on the router which I was able to connect in to, so, I guess the troubleshoot package won't help? (If it does, I'll happily do this). The other routers, unfortunately, due to the festive period and availability, we have instructed onsite staff to simply hard reboot when able - if I can get anyone to site, I will attempt to do so. (I take it that after reboot is useless?)
There are no data limits on the sim... I have full control over them and there is no limit set. The moment I clicked "Reboot Modem" it came live.
FYI, not that helpful but please see here: Each "spike" is one hour:
1. is when I changed the sim from deactivated to activated on the network portal. There was no change for about 7-8 minutes and I was remoted in.
2. is the first Authentication request which happened immediately after I clicked "Reboot Modem"
3. Is the connection (and line above) to the network/fully established.
You can see that in the green area before, the sim was fully active/fully allowed to connect, but, the router just did not establish a connection and was reported "disconnected".
Going back in the logs by about a week, that is when we started having problems. Even when a sim is deactivated, the router constantly tries to authenticate and connect every few minutes as can be seen here:
However, after December the 18th (when the problems started), we can see that the router does not attempt to authenticate or do any sort of connection.
Going however to one of the working routers, we can see usual behaviour:
These routers were rolled out in a batch 8, 3 of which are fine (as the picture directly above), but, 5 of which on the exact same day, stopped sending out authentication requests - I just wondered if you know of any other reason that can cause this as I've drawn a blank and am very worried that there may be other issues here.