I created an Action, made a shortcut key combo for it via the Action Options panel.
It worked fine, right up until I made a shortcut for
Object>Path>Remove Anchor Points...
I assume this is because when I made this new shortcut it asked me to create a new shortcut set, so I did.
Now, no matter which shortcut set I use, the (still registered) shortcut for the Action doesn't work. WHY?
If I reset it, it still doesn't work. It's acting as though the Action no longer exists, but it's right there in the Actions panel, with the shortcut still set.