Thanks for the additional info on that vaulted volume.
With an Access state of Offsite, the Move Data should operate on local
primary pool volumes containing the same data.  Whereas that didn't
happen, it calls into question the state of the online volumes or
whether the TSM database contains entries for any files on that
offsite volume.  I'd start by performing a Query CONtent on that
volume, and then add DAmaged=Yes, to see if something strange going on
there: it's not impossible that the volume % utilization suggests data
on the tape but, due to problems, the database has no info for any
files on the tape.  For completeness, perform queries on the storage
pools themselves, to assure no odd state.  If a repeat of the Move
Data produces the same non-results, attempt on similar volumes to see
if there is a more widespread issue, and see if any further Activity
Log messages are produced to lend clues.  Hopefully, the library is
not now returning bizarre indications to the TSM server for volumes in
certain locations in the library.  You might want to review the TSM
Activity Log at restart time, when it would have tested the inventory
of the library.

   Richard Sims