Hello,
Could you clarify if you have enabled remote SSH and remote CLI access in the same Access Control menu?
Also, make sure you are reaching the device from a remote network (not the LAN network of the RUTX50).
If you have access to the WebUI of the RUTX50, I will ask you to navigate to System → Administration → Troubleshoot and generate a troubleshoot file. This file can be attached to your question and will only be visible to Teltonika moderators.
Best regards,
DaumantasG