If you just use the filemanager as usual, note that udisks2 is used there and will be in conflict with systemd.
I would advice you to automount after login, not on boot time. Just add:
udisksctl mount --block-device /dev/disk/by-uuid/76881290-a492-4fe5-8683-38f7a82151ad
to your startup apps (autorun) and it will be mounted automatically when your Desktop starts, after the login. No root permissions needed.
It is exactly the same as you would manually click on “1.9TB Volume” on the sidebar.
When you click on “Data” then it is a bookmark which contains your old path, which is used with udisks2 so the filemanager. Obviously that path doesn’t exist.
In systemd you mount it to /data. Now you need to create a bookmark for /data.