Hi and welcome to the site, I’m Louie. Sorry you had to wait awhile but I’ll do my best to help.
Initially, a possibility is that the paper sensor in the output tray is stuck and falsely sensing.
Try cleaning or even spraying the inside of the output bin with compressed air.
Likewise, exercise / close the output tray by pressing the open/close output tray button or by hand, if necessary. a couople of times.