Set all the properties of the view before adding it to its superview.
UIView *containerView = [transitionContext containerView];
_authorizationVC.view.frame = CGRectMake(10, 30, 300, 450); /// Change the frame FIRST!
[containerView addSubview:blurredView];
[containerView insertSubview:_authorizationVC.view aboveSubview:blurredView];
Voila! The nav bar acts as expected.