I made a key command that is not working

I have made plenty of custom key commands on Dorico, but this one is not working.

I set “Filter->Deselect Only” to Alt+D.
You can see that here in the menu:

My alt key and D key have been tested independently and each confirmed to work properly, but pressing “Alt+D” will not switch the filter from “Select Only” to “Deselect Only”.

Ideas? Anyone else encounter a similar problem?

Alt D is “Select None” by default. Have you removed that one?