Processed Leave Reversal

There are cases employee requested a leave but didn't take it. And the payroll has completed final update for the requested leave date.

Our HR department is asking if employees can submit the offset (negative) leave request to the supervisor to be approved to reverse the processed but not taken leaves.

We did a test. The employee has no issue submitting a negative hours leave request. But when the supervisor approved the leave request, we received an error even though the leave request was still approved.

Is there anyone having the same business case? Can anyone share what is being used to reverse the 'processed but not taken' leaves? or is there anyone using the same method we are trying? Any practice sharing will be much appreciated.