I am afraid that the issue is not from the RMS side in this case as after the developers restarted uhttpd(web ui) service the device becomes reachable.
In this case it seems that for some reason the reboot turns off uhttpd service on the device, which is a strange behavior of the device. I believe that currently the only viable solution would be to restore the device to default settings. I do understand that the device is located in a remote location, therefore, it might not be accessible after that(it might not connect back to RMS).
Therefore, it would be best to carry such procedure when you are physically able to reach the device so you could manually configure it to connect to RMS if it wouldn't connect back automatically after restoring to default settings.(Sometimes it happens, that devices loose internet connectivity after restoring to default settings, for instance, if a custom APN is used).
Therefore, if possible I would recommend to go to the location and do the procedure. Restore to default settings check if the issue reoccurs, if it does upgrade to my earlier mentioned firmware version that I have forwarded to you via private message earlier and check if it still reoccurs. If it does, download the troubleshoot file and forward it to me.
Alternatively, the device now is reachable, so until the reboot it should work without a problem. In addition, there are SMS utility commands that Could be sent to the router: https://wiki.teltonika-networks.com/view/RUT955_Mobile_Utilities#SMS_Utilities
Among the commands here is a list of commands that you should look for:
- restore - restores the device to default settings, this might be useful since you could run this command, there is a chance the device will connect back to RMS, however, if it doesn't you would have to go to the location and access it manually.
- rms_off/rms_on these commands turn the RMS service off and on. It could be used to remotely restart RMS via SMS commands.
- rms_connect - forces the device to connect to RMS, Could be used after the restore command, if the device isn't connecting back to RMS, you could try forcing it with this command.
By default the commands are being executed by device admin password with the following Syntax:
(admin password) (command)
For example: admin01 restore
Note: to send the commands you would need to know the phone number of the Sim Card, in order to find it out the easiest way is to send an SMS to yourself, more information here: https://wiki.teltonika-networks.com/view/RUT955_Mobile_Utilities#Send_Messages