nice @Nige_S , I found the action, it was a simple 'activate application keyboard maestro' , I deleted it and inserted a 'fresh' one, now it doesn't time out.
most excellent....
sidebar: I was here before, that when I close the editor, KM crashes. I open it again, it crashes. If I hide KM, it is ok.
Last time (2 days ago) it stopped after I restarted, but I can't restart just now till later... all just FYI......