> What was the primary reason for update via bootloader menu?
This is to confirm the operation of RUT240 with TELTONIKA's firmware, which may be faulty.
> Does the device save other settings than the password?
No.
> Do the settings remain after device reboot?
I can't check because I can't change the admin password and also cannot use WebUI.
> Could you attach a troubleshoot file to your question?
>To generate the file, first, replicate the issue, then access router's WebUI, go to System -> Administration -> Troubleshoot section and download troubleshoot file from there. The logs in the file might provide more insight into the issue.
I cannot, because I cannot use WebUI for this RUT240.