As the title says, you can’t set the navigation rules on a UUserWidget itself from the editor panel, or any rule you choose reverts to “escape”. Some widgets which you absolutely don’t want to navigate out of (think menu on top of a menu, or a blocking dialog panel) do need the navigation rules to be set to “Stop”. The current workaround is to get the root widget added to its hierarchy and set the rules there, during PreConstruct. This is rather ugly since we can’t (or shouldn’t) do this during the c++ constructor of the UUserWidget and are writing settings to another innocent widget during PreConstruct.
Request: Make it possible to set navigation rules on a UserWidget level.