Zombie servo drive - DMM Tech servo drive settings

Hmmm. Left the machine powered up (with the e-stop depressed for safety) and came back to find the X axis unresponsive. The drive was still functional (leadscrew held firmly in position) and the controller was trying to drive it but nothing doing.

Connected up the comms software and it seemed to have defaulted to RS232 rather than the step/dir scheme it had been running. How the f*ck can it change that?? The comms lead wasn't even connect up.

Changed it back and all is good again. But when can I expect this to happen again?

For the record, here's the settings screen for both X and Y axes:

Not unduly impressed by this.....