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.
Maybe your script is in an endless loop?
So, please upload your macro, or if it is not in a macro, then your script using a Code Block.
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.