Haven't seen that before, can't find anything related in the release notes (for 6.5.4.8, latest in branch) either.
If you can easily upgrade to the latest version, I would give that a try so you can verify if the issue is still there, and have a better starting point for further troubleshooting. Also, 6.5.4.8-FIPS is a Conservative Release. If an upgrade is not easy, leave it at this version for now.
Please open a case with Aruba TAC Support to get this investigated.