Hello,
No known, reproducible issues of this kind are known.
Does the issue occur for this a single device or are there more?
How do you recover, does a simple reboot work, or do you have to reset the device to factory defaults?
Could you enable logging to router's flash? This would allow to save device logs, if the device reboot is mandatory to recover.
To do this, login to router's WebUI, navigate to System -> Administration -> Troubleshoot -> Logging settings. Set option Save log in to Flash memory.
Then, wait till the issue replicates. After you are able to login again, access router's WebUI, go to System -> Administration -> Troubleshoot section and download troubleshoot file from there. Attach the file by editing your question.
The logs in the file might provide more insight into the issue.
Attached files are private and visible only to Teltonika Moderators.
Best regards,