In PopupMenu::addCustomItem documentation:
Appends a custom menu item that can't be used to trigger a result. This will add a user-defined component to use as a menu item. It's the caller's responsibility to delete the component that is passed-in when it's no longer needed after the menu has been hidden. If triggerMenuItemAutomaticallyWhenClicked is true, the menu itself will handle detection of a mouse-click on your component, and use that to trigger the menu ID specified in itemResultID. If this is false, the menu item can't be triggered, so itemResultID is not used.
This is no more the case as the PopupMenu::CustomComponent is a SingleThreadedReferenceCountedObject ?
I got this cause i was trying to delete the object myself... and finally banged on this.