"Ctrl + scroll wheel" zoom not working properly

I'm used to zooming by holding the ctrl key and then scrolling with a mouse.

However, this feature works randomly. Sometimes, it goes a couple of zoom levels, sometimes just scrolls the page as if ctrl wouldn't be pressed at all.

Oddly enough, I have the exact same problem in chromium, but yet have been unable to find a common denominator between the two.

(OS: Ubuntu 18.04.4 LTS, Arch.: x86_64, MuseScore version (64-bit): 3.2.3+dfsg1-4~ppa1804+1 (Ubuntu bionic/amd64), MuseScore build number not set, revision: d2d863f)

Edit:
It appears that also the shift key (which is supposed to change the scrolling direction) isn't working either.