Presenting ViewController with transparent background

I've got a menu UIViewController I slide in from the left. (Client requirement). Targeting 13.1 in Xcode 11.1.
The issue I have is when I slide it in with my custom transition it hops down about 20 pixels. If I set the top of the presented ViewController down 20 pixels before sliding it in it doesn't do the hop. It looks like it's trying to fo the new card-like presentation.
Using the UIModalPresentationStyle.fullScreen doesn't stop the hop. I need the transparent background anyway so UIModalPresentationStyle.overFullScreen or UIModalPresentationStyle.overCurrentContext are required anyway.
I have a suspicion this is navigation bar related. The presenting UIViewControllers have navbars and the presented UIViewController does not.
Any help would be appreciated.

class SegueFromLeft: UIStoryboardSegue {

    override func perform() {

        let src = self.source
        let dst = self.destination

    // The offset is the starting y for the menu ViewController   
var offset:CGFloat = 44.0 // good for iPhone 11
        src.view.superview?.insertSubview(dst.view, aboveSubview: src.view)

        dst.view.transform = CGAffineTransform(translationX: -src.view.frame.size.width, y: offset)

        UIView.animate(withDuration: 0.35,

                  delay: 0.0,

                  options: .curveEaseInOut,

                  animations: {

                    dst.view.transform = CGAffineTransform(translationX: 0, y: offset)

                    },

                        completion: { finished in
                        src.present(dst, animated: false, completion: nil)
                    }
            )
    }
}