When creating a full-screen modal with the ModalDialogService, the StatusBar changes do not go on the modal but on the page behind it. You can tell this by hitting the back button, and the changes persist on the previous page (as mentioned in this issue).
When creating a full-screen modal with the ModalDialogService, the StatusBar changes do not go on the modal but on the page behind it. You can tell this by hitting the back button, and the changes persist on the previous page (as mentioned in this issue).