I have similar problems with my workstation 6605DN.
It is just bad quality of Xerox printers and Xerox is not intersted in providing a good service. They even don't respond to my service requests. Finally repairing is more expensive than throwing away. Xerox do no care about climat and waste generation.
I am having same issue new unboxed printer setup and jamming
ERROR CVT SIMPLEX #1 EXIT SENSOR OFF JAM
Everytime I try to scan something to my e-mail from the very top feed location it jams with less than 1/4 of the piece of paper left to roll out. It's like the last roller isn't working or is stopping too early. Tried restarting and opening covers to check for blockages. This printer is literally brand new.