Hi,
Ok, Odd, it all works fine, Can you tell me exactly what's not working? It's likely that you don't reference the name properly ( maybe a trailing space or some typo).
To test this, copy paste from the modifier component directly and test on a dedicated scene with just the morph and a simple fsm with manual control.
Let me know how it goes. Else can you send me that test scene with your morph, maybe it's special and I don't have the same type of rig ( unlikely, but you never know)
Bye,
Jean