Trouble Adding USB Drive to Bazzite (Steam)

I’m trying to add a SATA SSD in a UGREEN USB external enclosure but having difficulties….

No matter what I try, when I go to Storage in Bazzite’s Steam Big Picture mode, I see the drive but it just says I need to format it. I can format it and it stays the same, asking me to format.

I tried going into the desktop mode, formatting, even mounting the drive to /var/mnt/steamlibrary (create a new directory, and mount it in the Disk util). But still it just says I need to format the disk before using it when in big picture mode.

So I drop back to desktop, run Steam from there and then I can add the disk in the Storage settings in Steam no problem! I can move games over to the new drive.

Shut down desktop Steam and restarted Bazzite big picture view and all good - the new drive is there and recognized.