Hi Leo,
There is a problem with the overlay (non-persistent) scrollbar: it is not possible to detect its actual height. So the Scheduler uses a guess value (which is now 14 pixels). If it doesn’t match the real scrollbar overlay, it can lead to weird effects like this.
The real and reliable solution is to to add a persistent scrollbar to the Scheduler scrolling area using ::-webkit-scrollbar { height: ... }. That makes the scrollbar permanently visible and the height can be detected reliably. You can try adding it to the CSS to see if it works for you.
Another option is to expose the fallback height value as a property. But you still can’t be sure what value to use on different systems.