Quote
#define Y_PROBE_OFFSET_FROM_EXTRUDER 56 // Y offset: -front +behind [the nozzle]
Is this not expecting the Y0 position to be at the front of the bed, the way you have your Y home set, this should be a negative value(i think)
You would be better setting your Y home (as you have it) to max so that X0 and Y0 will be at the front left of the bed otherwise your prints are going to come out reversed.
