@Tinchus you say your endstops are NC, however as you have inverted the corresponding inputs in the M574 command, if they are simple microswitches then they must be NO. Endstops wired as NO are very susceptible to capacitively coupled interference. My guess is that the endstop wires are running close to the BLTouch wires and picking up interference from the BLTouch control signal.
Either change the switches to use the NC contacts, or use shielded wire for the endstops.