instantAction 'cancelOrder' does not trigger NavigationHandler.cancel() method

I have implemented and registered a navigation handler based on vda5050pp::handler::BaseNavigationHandler, but when during an active NavigationTask the instantAction cancelOrder is sent, Its cancel method is never called and the order is not cancelled correctly.

Is that behaviour wanted? Am I supposed to handle the cancelOrder action by myself? Cause it seems like such actions are not ment to be handled by self implemented action handlers ...