@dc42 @WolfMc3 Belatedly, I have created this Github issue: https://github.com/Duet3D/RepRapFirmware/issues/1058
Ian
droftarts created this issue in Duet3D/RepRapFirmware open [bug]: RRF 3.5.3 - Extruder drives on mainboard-as-expansion-board not moving #1058