For this issue of yours may I know if you made changes in the devices what configurations did you touch? Did you add some custom scripts also?
If all of those is no, could you try re-flashing the firmware via the bootloader menu and see if it helps :)
How to flash firmware via Bootloader menu: RUT950 Device Recovery Options - Teltonika Networks Wiki (teltonika-networks.com)
Note: Upgrading the device firmware from the bootloader menu wipes all configurations.