You know what..... I think I’ve demonstrated my stupidity to all... on further testing it’s my dust extraction. I just made the assumption it was the cnc as clearly the dust extraction is always on when that is.

I only realised this when I had my little lad hoovering my shop floor while I was on the pc. That’s the only time the dust extraction has been on when the cnc wasn’t and I’ve been using the pc!

So to rephrase my question, with a wired mouse and keyboard, how do I stop the interference issue when my dust collection is on?