Once there is a tested process for stopping the printer in case of something going wrong, send a G28 X Y command. This will only home X and Y but not Z. The tool head should *move up slightly and then move to the right until it hits the X endstop, then move to the back of the printer until it hits the Y endstop. In a CoreXY configuration, both motors have to move in order to get the toolhead to go in only and X or Y direction (think Etch A Sketch). If the gantry moves downward first before moving to the right, you must reverse your z stepper directions in the config.
Can we add to https://docs.vorondesign.com/build/startup/#xy-homing-check
Once there is a tested process for stopping the printer in case of something going wrong, send a G28 X Y command. This will only home X and Y but not Z. The tool head should *move up slightly and then move to the right until it hits the X endstop, then move to the back of the printer until it hits the Y endstop. In a CoreXY configuration, both motors have to move in order to get the toolhead to go in only and X or Y direction (think Etch A Sketch). If the gantry moves downward first before moving to the right, you must reverse your z stepper directions in the config.