Hey there,
I just switched to a new machine, shucked one of the drives that was previously in an external USB enclosure, added it internally in the new case, and found that the UUID had changed from doing so, disallowing me from starting my array. So, I went to Tools -> New Config, reset my config, re-added the disk afterwards, and found that the disk is showing FS auto (rather than XFS), and Unmountable. So, I ran the xfs_repair tool via Unraid console on the disk, which appeared to show no errors or issues at all, really. And, when mounted as an Unassigned Device, all my files are still there.
What gives? From the past two hours of reading I've been doing, the xfs_repair should be the ticket. But, nothing changes.
I just added a bunch of new drives to the array as well (this issue was occurring before adding the new drives to the array, they were sitting in Unassigned Devices when I first tried New Config, etc.) so I'm debating just copying everything over from the drive to another one, but I'd much rather just get this working, instead.