I had a legacy iPad project that began having issues with views opening in a ‘modal’ window instead of full screen. Technically, they were being instantiated as modals, but since IOS 13 the modal view is what will be presented when using instantiateViewControllerWithIdentifier. It’s a simple fix:

if (@available(iOS 13, *)) { 
   nextPage.modalPresentationStyle = UIModalPresentationCustom; 
}

Unfortunately when you dismiss the view you instantiate using this, it’s parent view no longer receives a viewDidAppear event. So I had to add a call to viewDidAppear before running dismissViewControllerAnimated like so:

if (@available(iOS 13, *)) { 
    [self.presentingViewController viewDidAppear:false]; 
}