"=" doesn't work in shortcuts on italian keyboard

By default, "=" toggles a natural/bequadro symbol and ctrl+= zooms in, but neither work on an Italian keyboard. I tried to clear the shortcut and set it again, but nothing changes.
For info, on the italian keyboard = is done by pressing shift+0. That being said, using the other shift+number combinations (which all correspond to a symbol) works for setting up the shift+alt+number shortcuts for adding a note in the same chord below the select one... though in that case there's two different problems: 1. that's supposed to be the default, but it's missing by default and 2. those keybindings disappear any time one closes and reopens the application (which is annoying since I have to do it every 20 min due to playback bugs)