iOS26/SwiftUI long navigation titles?

In my SwiftUI iOS app, I use the following code int the app init to scale navigation titles:

    //Set large fonts in nav titles to size down if too long.
    //Otherwise get "Some Really Really Long..."
    //Maintains animation transition from page title to header
    UILabel.appearance(whenContainedInInstancesOf: [UINavigationBar.self]).adjustsFontSizeToFitWidth = true

Titles are set in the standard way:

    .navigationTitle(“Title")
    .navigationBarTitleDisplayMode(.large)

When built for iOS 26, and the titles are not scaled (in the simulator, at least). Is there another way to scale the titles that iOS 26 respects? Is this a temporary bug or due to an underlying framework change?