iOS 26: Header slightly shifts position shortly before animation ends

Description

Hi,
on iOS >= 26 it looks like the animation for the header is bugged. When the previous screen from which we're navigating from doesn't have a header, the next screen header is not animated correctly. There's a slight shift at the end of the animation (and it doesn't look good).

I've included the video of how the issue looks like. First tab shows bugged animation, second tab working one.

https://github.com/user-attachments/assets/ed460124-3408-43f5-bf28-8a6349940a75

Steps to reproduce

I've pasted the url to the GitHub repo to make the reproduction easy.

1. Fetch repo
2. Run npm install
3. Run npm start
4. Click on the button shown on different tabs to see different behaviours between different variants of the screens. (HomeTab and SettingsTab shows incorrect animation, ProfileTab shows correctly displayed animation).

Snack or a link to a repository

https://github.com/Ejden/react-native-navigation-bug-report

Screens version

4.16.0

React Native version

0.81.5

Platforms

iOS

JavaScript runtime

Hermes

Workflow

Expo managed workflow

Architecture

Fabric (New Architecture)

Build type

Debug mode

Device

Real device

Device model

iPhone 14 Pro (iOS: 26.2.1)

Acknowledgements

Yes

Start with the linked react-native-navigation-bug-report repository: run npm install and npm start, then compare the HomeTab, SettingsTab, and ProfileTab navigation animations on iOS. Use the reported React Native 0.81.5, react-native-screens 4.16.0, Fabric, and Hermes setup to reproduce the shift. Done means the HomeTab and SettingsTab headers finish their transitions without the visible end-of-animation movement.