Scrolling in siderbar can get stuck

[microbit-matt-hillsdon]

Dubious repro (@microbit-robert couldn't match it):

In Chrome on Mac with a mouse with a mouse wheel:

1. Open Loops.
2. Size sidebar so the Loops description wraps
3. Position mouse under the header on the RHS of the sidebar
4. Scroll up/down repeatedly until you can't (~10 times for me)

[microbit-carlos]

I've had this issue before! I can reproduce now as well with these instructions, but it usually works again when moving the mouse a bit.

[kmcnaught]

Scrolling always gets stuck when a code block is highlighted, regardless of wrapping. Code blocks get highlighted when hovered over, which can trigger unintentionally during a "scrolling while skim-reading" action and give the appearance of sporadic behaviour.

Is this the same issue discussed here? Video demo: https://www.loom.com/share/25f1ff1e15434badbe4a5d6387dafe11

[microbit-matt-hillsdon]

I think these are separate issues. @kmcnaught's issue is known and we've tried to mitigate. We're limited in what we can do with the current approach to popping up the code overlay on hover. The obvious way to implement with z-index had problems with scrollbars on Safari.

The issue in this ticket is unrelated to being over the code embed at the time you try to scroll. I couldn't reproduce it just now.