When the system font size changes, the text sizes in the application are not updated

[nexquery]

Description

Please watch the video to understand the issue better.

import { View, Text, StatusBar } from "react-native";

export default function App() {
	return (
		<View style={{ flex: 1, justifyContent: "center", alignItems: "center" }}>
            <StatusBar animated={true} translucent={true} barStyle={"dark-content"} backgroundColor={"transparent"} />
			<Text style={{ fontSize: 14 }}>Hesap Defterim</Text>
		</View>
	);
}

https://github.com/user-attachments/assets/4254a949-f596-4e64-bf43-58f51fd3842c

Steps to reproduce

npx @react-native-community/cli@latest init TestProject --package-name com.test.project npx react-native run-android

React Native Version

0.81.4

Affected Platforms

Runtime - Android

Output of npx @react-native-community/cli info

System:
  OS: Windows 11 10.0.26200
  CPU: "(24) x64 AMD Ryzen 9 7900X 12-Core Processor            "
  Memory: 12.94 GB / 31.60 GB
Binaries:
  Node:
    version: 24.9.0
    path: C:\Program Files\nodejs\node.EXE
  Yarn: Not Found
  npm:
    version: 11.6.0
    path: C:\Program Files\nodejs\npm.CMD
  Watchman: Not Found
SDKs:
  Android SDK:
    API Levels:
      - "36"
    Build Tools:
      - 35.0.0
      - 36.0.0
      - 36.1.0
    System Images:
      - android-36.1 | Google Play Intel x86_64 Atom
    Android NDK: Not Found
  Windows SDK: Not Found
IDEs:
  Android Studio: AI-251.26094.121.2513.14007798
  Visual Studio: Not Found
Languages:
  Java: 17.0.16
  Ruby: Not Found
npmPackages:
  "@react-native-community/cli":
    installed: 20.0.0
    wanted: 20.0.0
  react:
    installed: 19.1.0
    wanted: 19.1.0
  react-native:
    installed: 0.81.4
    wanted: 0.81.4
  react-native-windows: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: Not found
  newArchEnabled: Not found

Stacktrace or Logs

N/A

MANDATORY Reproducer

N/A

Screenshots and Videos

https://github.com/user-attachments/assets/4ca8e5d4-6564-41ea-aae8-4c76d6de93e3

[react-native-bot]

[!WARNING] Missing reproducer: We could not detect a reproducible example in your issue report. Reproducers are mandatory and we can accept only one of those as a valid reproducer:

• For majority of bugs: send us a Pull Request with the RNTesterPlayground.js edited to reproduce your bug.
• If your bug is UI related: a Snack
• If your bug is build/upgrade related: a project using our Reproducer Template

You can read more about about it on our website: How to report a bug.

[erenkulaksiz]

does restarting app fixes the issue?

[nexquery]

does restarting app fixes the issue?

When I restart the application, the problem is fixed.

Uygulamayı yeniden başlatınca sorun düzeliyor.

[Racha2004]

could not reproduce as the reproducer is missing. instead reproduced issue creating a sample app. platform:Android

[devanshsaini11]

@nexquery Can you share a valid repro using Reproducer Template so it can be validated quickly

[RizzoG99]

Same issue on my Mobile app (Android - iOS). @nexquery have you find any solution?

[nexquery]

Same issue on my Mobile app (Android - iOS). @nexquery have you find any solution?

This problem seems to be fixed in version 0.82.1.

[RizzoG99]

@nexquery I have the same problem in latest version on iOS. @devanshsaini11 I have created a repo to reproduce the problem: ReactNativeFontSize

On my own app if I have the app opened and I change font size by opening a new page the screen show correctly. Because it is a new instance. But with the view already created It seems that the text container doesn't update height and width.

[nexquery]

@RizzoG99 This issue is not fully resolved in version 0.82.1.

[losikov]

System theme changes don't trigger useColorScheme() or Appearance.addChangeListener() on iOS

On React Native 0.81.5, when the system theme (light/dark) changes while the app is running, neither useColorScheme() nor Appearance.addChangeListener() fires. The app only reflects the system theme after a restart.

Steps to reproduce:

1. Run app on iOS
2. Change system theme in Settings
3. Return to app
4. useColorScheme() still returns old value
5. Appearance.addChangeListener() callback never fires

React Native Version: 0.81.5

Affected Platforms: iOS only.

[priami93]

Same issue here with 0.79.2

[RizzoG99]

Hi guys! ✋🏻

By testing on physical Android (a Samsung Note 9 with Android 10) and by changing the system font size the app doesn't update and the font size remains the same 😕.

On the emulator side, with Android 15, the system font size changes triggers the android activity update 👍🏻.

I reproduce the problem with a vanilla project: ReactNativeFontSize.

[MarkusAbtion]

I have this same issue. The UI doesn't update before the app has been completely closed and reopened.

[rknastenka]

Related #52895