Using Grbl 1.1f , distance .25 in mode , when using the keypad with Numlock ON:
Press the 8 key the Y axis moves as expected. Press 8 again and Y axis moves about 1/2 the first distance. Press 8 again the Y axis barely moves. Press again , no movement.
Press the 2 key and Y axis moves as expected. Press again , NO movement.
Press the 6 key and Y moves and X moves. Press 6 again Y moves about 1/2 distance then no movement.
Press 4 and x moves neg as expected. Press again no movement.
Press 6 again and repeats the full ,1/2 , no movement.
If I alternate between 8 and 4 the Y axis moves back and forth(+ and -)
if I alternate between 4 and 2 I usually get no movement .
some movement change biased on last key pressed.
There are obviously many more combinations but the point is very few are as expected.
I get this same response from 2 different grbl machines using two different computers.
Any thoughts would be appreciated.