Please try this:
Stop array, select each data disk and set its file system type to "xfs".
Start array, and then click Format, let it complete and observe that all disks 'mounted', everything looks good.
Stop array, select each data disk and set file system type to "xfs-encrypted" (all 3 of them).
Start array, observe that all 3 data disks should show 'Unformatted'. Enter your encryption key and click Format.
At this point, all should show up as encrypted and mounted. Buf if not, please capture diagnostics at this point and post here.