Since some time I have issues with ADF scanner on my M277dw. Feeding itself seems to be working fine, but once pages are scanned, there seems to be something wrong with mechanism that puts them on the tray. When scanning just 6 pages, they are being pushed off the tray.
There is plastic switch on the tray to prevent pages being dropped off. When I turn it up, pages stay on the tray, but it can be seen they are being put on it in the reverse order. This severely undermines the 2-sided scanning functionality.
This behavior can be seen here:
I am using official HP Scan software on Windows. One thing that I remember that one day I saw a small black plastic rubber seal pushed out from the printer that looked like this. Could it have something to do with it?
Any ideas what can I do to troubleshoot this issue?