Comment 6 for bug 1800577

>> Do you use any other Qt applications? Have you noticed the same issue with those?
Hm, I think RStudio uses Qt and while I didn't find the identical bug, I do observe a different scrolling bug in their file viewer.

>> What version of Qt did you build with and how did you install it?
5.10.1 installed view homebrew (`brew install qt5`)

I realized I was mistaken before when I said I had my MacOs settings set to always show scrollbars. Setting to "always show" actually eliminates the problem, whereas the problem emerges under the default "auto show" setting.