Why are Dynamic multicast delegates not overridable if declared in Actors?

I have a C++ AActor class where I declared a public dynamic multicast delagate with BlueprintCallable, BlueprintAssignable, BlueprintReadWrite.

When I edit the blueprint derived from this class I don’t see the green + button that allows me to override it in the blueprint.

This is working fine if the delegate is delclared inside an actor component and when I click on the component I see the buttons.