Just a quick update, the start orb animation works correctly when the task bar is dragged to the sides or top of the screen. The animation only resets when the task bar is at the bottom, which is making me think its because of the win-x menu. I have also tried removing all the win-x menu shortcuts from appdata, which had no effect.
edit: here is a quick image to show the mouse dead zone of the animation.
edit2: I have found that if you shutdown windows with the task bar on the side, then drag it back after reboot, the animation works perfectly for about 20 minutes before breaking again.
I hope this information is useful.