Diacritical accent menu no longer showing up following clean install

Hello there, first post on BTT Forums, please excuse me if I fail to include any necessary information :-\

I have recently moved to a Macbook Pro and I have bought BTT in order to improve the use of the touchbar. So far, so good.
However, yesterday a new "issue" (not quite sure this qualifies as a bug) showed up. Before installing BTT, press-and-hold of some keys would prompt a diacritical accent menu. Following installation, such menu is no longer showing up. I uninstalled BTT and the menu came back upon restart; I have then reinstalled BTT, and the menu is no longer showing up.

Additionally, some shortcuts are not working properly (issue solved - see below). If I try and record a Fn + W combination for (say) screen full size, BTT records it just fine, but then nothing occurs when I press Fn + W. Using other combinations (such as ctrl+W) works just fine.

These are both minor issues and of course I can live without these, but I was wondering if there is any way to "fix" this.

MacBook Pro M1, Big Sur 11.5.2, Italian keyboard but eveything on the system is set on English language.


EDIT - The Fn key was resolved (it seems like Bitwarden triggers secure input, therefore blocking the use of the Fn key and - in case anyone ever faces the same issue - also prevents from recording key sequences)