Operator=yes does nothing?

I’m trying to setup the voicemail out to let a caller press 0 to get out to an operator.

With operator=yes I still don’t see anything when a caller press * or 0, does not even acknowledge it was pressed. I realise I have to have an “a” and an “o” extension in the same context as my mailboxes and I’ve done that but its not like Asterisk even realizes that 0 or * has been pressed at all.

ideas?

Thansk