From ByWater: When libraries accept payment on accruing fines and then backdate the checkin of the item, the final amount due can end up less than the amount paid. (There are other ways for this to happen, but backdated checkin is the most common.) It's not a fine that can be paid off (because it's negative), but it's not truly a credit either so it cannot be reconciled or voided. We would like to see this addressed so we can continue to backdate our overnight bookdrop items without these issues, and without having to constantly ask our support vendor to remove them for us.
This should be resolved as of bug 21747. The excess payment amount is moved into a credit. Do you have examples generated after you moved to 19.05?
(In reply to Andrew Fuerste-Henry from comment #1) > This should be resolved as of bug 21747. The excess payment amount is moved > into a credit. Do you have examples generated after you moved to 19.05? Check our support tickets. They have all been handled through Bywater because we couldn't do anything with them. I would think if it were fixed, our backdating wouldn't be touching it at this point.
I wonder if this is related to bug 22539?