can't use ctrl + alt + scroll wheel to change brush size

[akirapink]

i recently had to reinstall linux mint, and upon reinstalling GIMP 2.99, i discover that i can't use these keyboard? shortcuts anymore
and i can't assign them either, because the scroll wheel doesn't count as a key
what do i do to get those back?

the shortcuts in question being:
- ctrl + alt + scroll wheel: change brush size
- alt + scroll wheel: change brush opacity