On/Off MPG movement/bounce

Hello everyone,
I have a 3 axis cnc machine, and Im using a simple pulse generator to jog it around, but Im having an issue.. There is a on and off switch to turn the MPG wheel on and off. MPG has V+ , V- , A , B on it. If i cut V+ linuxcnc registers an impulse. If i turn it back on it also registers an impulse. The selected axis moves a single step in any direction. This can be fatal for the instrument the spindle is carryi​​​​​ng. I have an ilowpass filter set, but it still counts the impulse when turning the MPG wheel on or off. Ive also tried to cut A and B with two separate contacts and leave the MPG on but still does the same?

Next to the MPG there are also 3 push buttons for positive jogging, negative jogging and rapid jogging with highest speeds that are possible for the machine. They are working separately from the MPG..

MPG is runnung fine, its a 100 section/position working from 5v to 12v. Its mainly used as a remote and for precise movement. It does change direction whenurned CW or CCW. The issue comes when i switch it off and cut the power supply. It does 1 single step in a random direction on the selected axis. Does the same when supplied with power...