I just put all scrollbar issues here, no matter what sort of scrollbars they might be.
( Copy from https://ask.libreoffice.org/en/question/122670/scrolling-in-calc-is-slow-in-54-on-macos/ ):
After recent upgrade to 5.4 I'm struggling a bit with scrolling in Calc (under macOS) - it looks like it's very laggy (I would describe it as very "sticky").
Current version 126.96.36.199 still exhibits the issue.
I've noticed, that it's more noticeable with scrolling down (i.e. trying to see cells with higher indexes), scrolling up seems to be working fine.
I've just noticed - scrolling works just fine if... LibreOffice Calc doesn't have focus (so simply hovering over it's window and scrolling while other app has focus works fine)
This also is refers to scrollbar. Not directly, because it concerns more window frame width, or maybe it is a problem of specific vcl - gtk or gtk3-kde5 or qt5. The problem is that scrollbar is very narrow and it doesn't touch window edge and mouse can't touch scrollbar.