If this is the case then it’s almost certainly the known issue with rapid speeds in D1 firmware being set too high and unable to be changed.
Basically this affects any motion using G0 g-code command.
It could be the stepper simply can’t keep up with the requested rapid speed or the belts are still slipping. Either way, it’s not currently configurable as far as I know. Not sure if xTool is working on a fix.