Can anyone help before I take a sledgehammer to my machine? Im having some issues setting my limits up.

To start, im using a zp5a bob. 2 limits wired in series NC on each axis using a total of 6 switches and 3 inputs. Good so far? Now, when i go to setup in mach, I set my switches up to the correct pins. Ill start with x as an example first but all axis act the same. No switches on x are pressed, mach says 'limit switch triggered', so press the switch in, it goes away......right so switch working good, change active low setting to reverse right?....wrong. Says limit triggered no matter if switch open or closed?!? Checked switches with meter, all continuity test fine. So I change switches to NO config, no joy. Switch does nothing at all. So the only time i can get the switch to do anything is when its on a NC config, and active low OFF, then the switch operation is the wrong way round!