Sorry if this has already been noted, but I've gotten similar behavior when I've tried to trigger a macro by simulating its assigned hotkey trigger--just a beep and no response.
In this post, simulating a keystroke with System Events is mentioned as a workaround for doing this and includes a request for a "Trigger Macro By Hot Key" action.
The "Trigger Macro By Hot Key" action now exists.
You might try the action with the "Failure Aborts Macro" option in the 
drop down menu unchecked.
That way if there is no such hot key trigger assigned you'll get an error message saying something like:
Or, if there is an active macro that uses the trigger, the macro should fire and--if it's not apparent which macro it was--you can find it the Engine.log description of the last macro triggered.