At first, I could reliably print duplex on MX922. Over time it has increasingly failing with "1300" "Jammed in paper output" messages. I have never found any debris to remove. I have used flashlights, compressed air and a toothbrush to try to clean any dust that I can find in the accessible parts of the printer. Nothing helps. It prints ok without duplex.
I am printing from Linux (Ubuntu 16.04).
I chosse the duplex setting when I print. I did not set duplex from the driver. My assumption is that it should not matter where I set duplex, and that setting at driver simply forces all print jobs to be duplex.
