If the landlord uses a document feeder, there is something wrong. In fact, in my opinion, most file feeders have some problems. If the landlord wants to print on time, just put a copy on the glass.

If the glass is deformed, I'm afraid the exposure lamp assembly is deformed. Try cleaning it first. If not, I'm afraid you need to repair the exposure lamp assembly or adjust the complicated code to avoid the problem and try to adjust it in place.