To recreate: Have a bibliographic record with at least one item-level hold. Go to place one more hold (item-level or record-level, doesn't matter), but before placing the hold, cancel one of the item-level holds from the information tab in the requestspecific_info holdings table. When you confirm the cancellation, the next screen is a return to request.pl, but with no valid biblionumber, and the heading Place a hold on No bibliographic record. Backtrack to the initial record, and note that the cancellation did not actually complete. Observed in both 22.11 and 22.05, so likely an older issue.
This scenario comes up when we follow up on item-level holds that have been marked missing or have become long overdue. When we go to place a new hold on an available item, we see a link that says "Cancel Hold." Staff will of course try to use this tool to cancel the existing item-level hold that will never be filled, but the process doesn't complete because they're sent back to a blank request.pl page. Just IMO, a link that just plain doesn't work should be fixed. ;) Thanks!