Mystery Nav Controller?

I’ve set up a Nav Controller in the App Delegate, like so:

But when I go to add a View Controller onto the Stack, it doesn’t transition! Capture d’écran, le 2020-07-21 à 11.07.36 AM|689x78 ! Help is appreciated

I initialized the app as a tab view controller, but it is not set as the root view controller. Could this be the issue, and is there a fix?

“An app that uses a tab bar controller can also use navigation controllers in one or more tabs. When combining these two types of view controller in the same user interface, the tab bar controller always acts as the wrapper for the navigation controllers.”