Are the circled “Entrance” “Waiting” “Class2” supposed to indicate something? I do not see where this is being printed to the screen. Also there appears to be a node between the event node and the cast node. Can you explain what the node is doing? It is too small to in the screenshot.
As for the AI triggering the sound as well, if you use “Cast to Character” then anything that derives from the Character class will pass the cast call. If, by comparison, you used a “Cast to [MyUniquePlayerCharacter]” then the cast would pass for your player but would fail for your AI unless the AI class is a child of the MyUniquePlayerCharacter class.