I like to start or stop the animation by pressing keys on my laptop, instead of using my mouse. Sometimes it works, sometimes it doesn't. You cannot rely on it. I have to restart the program regularly to make it work.
Overall, the timeline is a bit buggy, in my opinion. When you click on some icons, e.g. the track list, track filter or the cross next to the track name, again, sometimes it works, sometimes it does not.