Can't override 'perform escape gesture' VoiceOver to block going back to previous screen

This is the situation: one of the flows in our app is a navigation stack that consists of several screens. At a certain point in this flow, one of the screens lacks a back button, because we don't want the user to go back to a previous screen in that flow. For sighted users everything works fine. But once a screen reader user activates VoiceOver and uses the perform escape gesture (2 fingers right-left-right) the app does go back to the previous screen!

We tried to override accessibilityPerformEscape (both in UIKit and SwiftUI) and do nothing in that method and in case of UIKit return true. That blocks going back when you're focusing on an element on the screen that belongs to the presented screen/viewController (not to the navigationBar).

But once the user is focused on the navigationBar and performs the escape gesture, the user can still go back. We tried to override again the accessibilityPerformEscape on the UINavigationController level and the UINavigationBar level but they are not even called.