I can't seem to create a working .desktop file when installing from source anymore

[David-Else]

Following the instructions that used to work:

cp contrib/Helix.desktop ~/.local/share/applications
cp contrib/helix.png ~/.icons # or ~/.local/share/icons

In Debian 12 nothing comes up when I start to search, including if I log in and out again. This means I can't easily associate anything on the desktop with Helix as the whole system revolves around .desktop files. I used to just set the file associations in Gnome files and it worked everywhere, including in nnn file manager using the terminal.

Any idea what has happened and how to fix it? Is it a Gnome 43 thing? I have been trying everything. Cheers!