I found it! add this code in your contentview file and it will work even if the bar is hidden or with custom elements:

extension UINavigationController: UIGestureRecognizerDelegate {

override open func viewDidLoad() {

super.viewDidLoad()

interactivePopGestureRecognizer?.delegate = self

}

public func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {

return viewControllers.count > 1

}

}

taken from this answer: https://stackoverflow.com/questions/59921239/hide-navigation-bar-without-losing-swipe-back-gesture-in-swiftui