In Studio, when the Assistant is working and I click the stop button, it appears to stop, but then starts back up again on its own. I suspect this is related to pressing the stop button in the middle of a tool call – the assistant probably starts again once the tool call finishes, even though it was supposed to stop…
I had to entirely quit Studio in order to avoid the assistant continuing on to attempt to start a playtest while I was still reviewing the script changes.