As @Phaedrux says. Usual practice on a CoreXY would be to home X and Y together (on a CoreXY it will stop when the first endstop triggers), then home X and Y separately, then home Z.
Many thanks to all. I guess I got it.
The x8 is a relic from the time I used TB6600s for the Z Axis and is just preliminary. I will change this later. Wish I would be that far already.