When editing a Circulation rule that contains a hard due date, the hard due date is removed upon saving unless the user re-enters or re-selects the Hard Due Date field before clicking the Save button. Steps to Reproduce: 1) Go to Administration > Circulation and Fine Rules 2) Locate an existing circulation rule that has a Hard Due Date configured 3) Click "Edit" on that rule 4) Modify any field in the rule (e.g., loan period, renewals allowed, fine amount) WITHOUT touching the Hard Due Date field 5) Click "Save" 6) Observe the saved rule The Hard Due Date should remain intact and unchanged when editing other fields in the circulation rule.