Ok, here's the latest, very interesting. I tried reversing the position of all 4 switches, 1 up, 2 and 3 down, 4 up. Rebooted the system, enrolled modules and the M1XIN disappeared so that didn't look good.
I reversed them again, 1 down, 2 and 3 up, 4 down, rebooted the system, enrolled modules...