Nice catch. I did have a quick look through the AXBB manual buy didn't spot that (the port/pin config looked suspicious but I've had Chinese motion controllers that ignore port/pins before so not entirely unrealistic). Not got/tried the AXBB myself - just keep your jumper setting in mind - unlikely but possible it'll mode on a reboot (your behaviour might be different next time you power-up... or maybe not), Peculiar that it doesn't behave as expected. You've set the max-spindle speed correctly, of course?