If I remeber correctly, Mach treats a 'home' switch differently than a 'limit' switch. A 'home' switch can also be a 'limit' but not vice versa or something like that.
It's been a while since I messed with this aspect, but in my setup I have only a single switch on each axis and Mach treats this as both home and limit. It functions as you describe you want . . i.e. it moves till it hits the switch and then automatically backs off the switch.
It appears you have told Mach that you have three switches all on the same pin. Unless you have three physical switches, you *may* need to use only 'home' on one end and 'limit' on the other as Mach is set up to 'back off' the home switch as you want.
You may also need to have the 'home' switches on one pin and the 'limit' on another, but I'm not sure about that. In my setup, Mach pays attention to the direction of travel and therefor knows which switch it is about to hit. I don't know exactly how the multiple switch per axis setup works.