Ok, I've tried this. I have a USB modem. When I look at /dev/tty*, I see an entry for ttyACM0. I ssume this would be the port I want. So, if I unplug the modem, the port disappears. I assume this is what is supposed to happen.
So, I connect the QIDI printer and look again. This time, ttyACM0 does NOT show up in the list. So there appears to be some kind of communication issue. Even if I disconnect the cable, R. Host still shows up as being connected After slicing , it says it's printing, except it never actually prints anything. Could this be a defective cable? Or possibly a firmware bug?