This is an issue with the scripts I have been creating, I had tried and tested them and not found a problem now running in keyboard maestro there is an issue.
One of the issues is which one is creating the issue?
I only know there is an issue from the mac slowing down and the activity monitor is not responding,
In order for us to help you, we'll need a lot more information.
I run many AppleScripts every day, some from Script Debugger, some from KM, and I have to say I have never seen that issue in Activity Monitor.
I do have one question: Are you using "osascript" directly? If so, why?
Then stop using the scripts, one by one, until you can isolate which one is causing the problem. I would probably stop all of them and then run each one individually.