To recreate: 1. Have item hold groups enabled. 2. Have a hold on an item group on a record. 3. Delete the item group - no warning of existing holds. 4. Hold is now a bib-level hold. In some cases, this may be desirable behavior (like a library using one record for multiple year editions), but in others, like volumes of a work, this now-bib-level hold is not what the patron needs. Best solution would be a warning with option for the librarian to either cancel hold or transform into bib-level hold.