iOS formSheet fitToContents includes header height when header is transparent

[Ubax]

Description

When using a formSheet with sheetAllowedDetents: 'fitToContents' on iOS, setting the native header to transparent appears to leave extra unused height in the sheet.

With an opaque header, the sheet fits the header plus content. With a transparent header, the header overlays the content as expected, but the sheet still appears to reserve the native header height, leaving dead space below the content.

In the transparent example you can see space below elements which is inset + header

Native context:

Looking at the iOS implementation, fitToContents is based on the RNSScreenContentWrapper frame height, then adjusted by contentHeightErrata.

That errata is accumulated while walking parent view controllers and adds the height of visible RNSNavigationController.navigationBar instances. The check appears to account for navigationBar.isHidden, but not whether the header is transparent.

Steps to reproduce

1. Clone and run the reproduction repository.
2. Open the "Opaque header" sheet.
3. Open the "Transparent header" sheet.
4. Open the "Transparent + header padding" sheet.
5. Compare the sheet content and the empty space below the last row.

Snack or a link to a repository

https://github.com/fabriziocucci/sheet-header-transparent-repro

Screens version

4.25.2

React Native version

0.86.0

Platforms

iOS

JavaScript runtime

Hermes

Workflow

Expo managed workflow

Architecture

Fabric (New Architecture)

Build type

Debug mode

Device

iOS simulator

Device model

iPhone 17 Pro Max simulator, iOS 26.2, Xcode 26.2

Acknowledgements

Yes

[github-actions]

Hey! 👋

The issue doesn't seem to contain a minimal reproduction.

Could you provide a snack or a link to a GitHub repository under your username that reproduces the problem?