I've examined your troubleshoot file, but couldn't find anything wrong or anything that could've caused your issue.
Firstly I would suggest you upgrade your firmware, as I've noticed you are using legacy firmware. You can download the latest firmware here: https://wiki.teltonika-networks.com/view/RUT950_Firmware_Downloads
If the issue persists after the FW update, send me another backup, but extract the backup only when you have a disconnect, otherwise, I will not be able to see what was the problem.
And one suggestion for your device security is don't leave an open port in your firewall to all of the internet, if you need an HTTPS port open for everyone, then change it to not so well known port.