Remove the server from the local machine. The server only goes on the backup location, the client only goes on the machine you with data you want to backup.
No sorry I’ve never used trunas for UrBackup. if you still get the error; make sure the permissions are correct and check the storage path in the server settings to make sure it all exists.
I had plenty of issues with a SMB share on my NAS (Terramaster TM423).
In my opinion there are too many reasons for failure using this method for backup.
So i switched completely to ISCSI. This method is professional and widely used …
I strongly recommend also using ISCSI targets…