Scrolling while viewing a file in a pull request will occasionally behave unexpectedly

I can't consistently reproduce this, it only happens some of the time and disappears once I refresh the page, but I thought I'd raise the feedback in case I'm not the only one to encounter the issue.

Please see the attached recording - I'm consistently "scrolling" vertically but if you watch the page contents or the scrollbar on the right, you can see occasional "jittering" in the opposite direction to where I'm trying to scroll.

You can see a horizontal scrollbar that flickers in and out of view in the recording, but the behaviour is the same even when there's no horizontal scrollbar (I tested on a larger screen with sufficient width).

I'm scrolling with the trackpad instead of a mouse, using a natural scrolling direction. When I reverse the scrolling direction, the scrolling no longer jitters with the occasional scroll in the wrong direction, but the scrolling isn't smooth - it'll speed up and slow down unexpectedly.