I guess, there could be a problem in Katalon Studio. Stopping a Test Suite Collection seems not to be robust enough. See Stopping executing test collection in KRE for similar issue.
Unfortunately this topic is in the “Announcement&Update, Documentation &Guideline” category; Katalon Developers may miss your post about a possible bug.
Could you create a now topic in the “Katalon Studio - Bug Reports” category? with more detail information what you found so that they can reproduce your issue on their side.
I do not see what you mean here.