If the stapled sheets are curled strongly or become limp after delivery, the trailing edge of the sheets may be too close to the paper exit when the paper is stacked.
If this happens, stapled sheets, when delivered, may push the previously delivered sheet, resulting in paper bending or misfeeding.
This is likely to occur if:
There is a tight curl on a delivered set of stapled sheets.
Limp paper such as thin or recycled paper is used.