Custom .desktop file not being used by Thunar?

Hi folks,

Okay so I'm not sure if this is normal behavior but I produced a custom '.desktop' file and placed it in ~/.local/share/applications/ . As expected, it work (is used) when launching the application from the Whisker menu, but not when launching a file associated to that '.desktop' file (standard mimetype stuff) from Thunar, despite the fact that Default Applications is saying to use that exact '.desktop' file.

When it gets superseded is it not also being superseded by Thunar? When I change the '.desktop' file in /usr/share/applications/ only then does my script work.

MOSTLY UNRELATED: As an aside (I've not been able to update for a while and don't even know if this is an Xfce app because) the Default Application app closes abruptly when a user clicks the Help button.

Above copied from the forums because I really need more time in my life, lol.

Love ya'll.