After upgrading to 6.12, the partition on my UD disk would not show its filesystem.
It's a local drive, not shared, formatted as xfs with encryption.
It would unlock the disk and mount the partition, but would error that it could not display the filesystem on the partition.
It also could not unmount, claiming the mount was busy. I had to stop the array to retry.
Reverted back to 6.11.5 and UD works correctly as it always has.