I have a milltronics retrofit. A fryer MB11 bed mill with a centurion 1 control. Recently the Z axis has been doing a plunge before moving in a positive direction. For example I was circular interping some counter bores and when I rapid out of the hole it dose a quick plunge about .005 deep before moving up. I'm thinking its an encoder. Even in handle jog once I reverse direction it jumps down. Dose anybody have any experience with this or know what this could be?