[Windows][ARM64] Touchscreen taps misaligned from widgets (large offset); mouse is correct — regression after 5f58b37fdaa

[dkmcgowan]

Steps to reproduce

On Windows 11 ARM64, install Flutter master at a recent framework revision.
flutter create touch_offset_repro
cd touch_offset_repro
flutter run -d windows (or flutter build windows and run the Release/Profile exe).
Use the touchscreen (finger) to tap the FAB and any tappable UI several times.
Optionally repeat with the trackpad/mouse: taps land on the intended targets.

Expected results

Finger touches should hit the same widgets under the finger as the mouse/trackpad (same as native Windows apps and same as older Flutter on the same machine).

Actual results

Finger touches still activate widgets, but the effective hit position is wrong by a large, roughly constant offset (on my device, on the order of ~1.5 inches on the panel). Mouse/trackpad is correct. Windows shell (Start, taskbar, other apps) is correct — only the Flutter app is wrong.

Regression check: On the same machine, checking out Flutter framework 5f58b37 (reported app version around 3.43.0-0.3.pre) and building/running the same project: touch is correct. So something regressed after that framework revision on master.

Code sample

Default flutter create template is enough (counter app). No custom code required. If you want a single-file sanity check, this is equivalent to the template’s interaction surface:

import 'package:flutter/material.dart';

void main() => runApp(const MaterialApp(home: Scaffold(body: Center(child: Text('Tap FAB with finger vs mouse')))));

Screenshots or Video

Screenshots / Video demonstration

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Logs

Logs

[Paste your logs here]

Flutter Doctor output

I pasted the first one where it's broken and the second output is where I found it still worked, so you can see where it stopped working

[√] Flutter (Channel master, 3.43.0-1.0.pre-570, on Microsoft Windows
    [Version 10.0.26200.8117], locale en-US) [1,771ms]
    • Flutter version 3.43.0-1.0.pre-570 on channel master at
      C:\Users\david\develop\flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision b1876d8b31 (12 hours ago), 2026-04-12 11:17:27
      -0400
    • Engine revision b1876d8b31
    • Dart version 3.13.0 (build 3.13.0-10.0.dev)
    • DevTools version 2.57.0
    • Feature flags: enable-web, enable-linux-desktop,
      enable-macos-desktop, enable-windows-desktop, enable-android,
      enable-ios, cli-animations, enable-native-assets,
      enable-swift-package-manager, omit-legacy-version-file,
      enable-lldb-debugging, enable-uiscene-migration, enable-riscv64

[√] Windows Version (Windows 11 or higher, 25H2, 2009) [789ms]

[√] Android toolchain - develop for Android devices (Android SDK version
    35.0.0) [2.5s]
    • Android SDK at C:\Android\Sdk
    • Emulator version unknown
    • Platform android-36, build-tools 35.0.0
    • ANDROID_HOME = C:\Android\Sdk
    • ANDROID_SDK_ROOT = C:\Android\Sdk
    • Java binary at: C:\Program
      Files\Microsoft\jdk-17.0.18.8-hotspot\bin\java.exe
      This JDK was found in the system PATH.
      To manually set the JDK path, use: `flutter config
      --jdk-dir="path/to/jdk"`.
    • Java version OpenJDK Runtime Environment Microsoft-13107724 (build
      17.0.18+8-LTS)
    • All Android licenses accepted.

[√] Chrome - develop for the web [223ms]
    • CHROME_EXECUTABLE = C:\Program Files
      (x86)\Microsoft\Edge\Application\msedge.exe

[√] Visual Studio - develop for Windows apps (Visual Studio Community 2026
    18.3.0) [222ms]
    • Visual Studio at C:\Program Files\Microsoft Visual
      Studio\18\Community
    • Visual Studio Community 2026 version 18.3.11505.172
    • Windows 10 SDK version 10.0.26100.0

[√] Connected device (3 available) [2.5s]
    • Windows (desktop) • windows • windows-arm64  • Microsoft Windows
      [Version 10.0.26200.8117]
    • Chrome (web)      • chrome  • web-javascript • unknown
    • Edge (web)        • edge    • web-javascript • Microsoft Edge
      146.0.3856.109

[√] Network resources [391ms]
    • All expected network resources are available.

• No issues found!

     [!] Flutter (Channel [user-branch], 3.43.0-0.3.pre, on Microsoft Windows [Version 10.0.26200.8117], locale en-US)
    [268ms]
    ! Flutter version 3.43.0-0.3.pre on channel [user-branch] at C:\Users\david\develop\flutter
      Currently on an unknown channel. Run `flutter channel` to switch to an official channel.
      If that doesn't fix the issue, reinstall Flutter by following instructions at https://flutter.dev/setup.
    ! Upstream repository unknown source is not a standard remote.
      Set environment variable "FLUTTER_GIT_URL" to unknown source to dismiss this error.
    • Framework revision 5f58b37fda (8 weeks ago), 2026-02-14 12:12:11 -0500
    • Engine revision 5f58b37fda
    • Dart version 3.12.0 (build 3.12.0-149.0.dev)
    • DevTools version 2.55.0
    • Feature flags: enable-web, enable-linux-desktop, enable-macos-desktop, enable-windows-desktop, enable-android,
      enable-ios, cli-animations, enable-native-assets, omit-legacy-version-file, enable-lldb-debugging,
      enable-uiscene-migration, enable-riscv64
    • If those were intentional, you can disregard the above warnings; however it is recommended to use "git" directly
      to perform update checks and upgrades.

[√] Windows Version (Windows 11 or higher, 25H2, 2009) [641ms]

[√] Android toolchain - develop for Android devices (Android SDK version 35.0.0) [1,449ms]
    • Android SDK at C:\Android\Sdk
    • Emulator version unknown
    • Platform android-36, build-tools 35.0.0
    • ANDROID_HOME = C:\Android\Sdk
    • ANDROID_SDK_ROOT = C:\Android\Sdk
    • Java binary at: C:\Program Files\Microsoft\jdk-17.0.18.8-hotspot\bin\java.exe
      This JDK was found in the system PATH.
      To manually set the JDK path, use: `flutter config --jdk-dir="path/to/jdk"`.
    • Java version OpenJDK Runtime Environment Microsoft-13107724 (build 17.0.18+8-LTS)
    • All Android licenses accepted.

[√] Chrome - develop for the web [178ms]
    • CHROME_EXECUTABLE = C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe

[√] Visual Studio - develop Windows apps (Visual Studio Community 2026 18.3.0) [177ms]
    • Visual Studio at C:\Program Files\Microsoft Visual Studio\18\Community
    • Visual Studio Community 2026 version 18.3.11505.172
    • Windows 10 SDK version 10.0.26100.0

[√] Connected device (3 available) [261ms]
    • Windows (desktop) • windows • windows-arm64  • Microsoft Windows [Version 10.0.26200.8117]
    • Chrome (web)      • chrome  • web-javascript • unknown
    • Edge (web)        • edge    • web-javascript • Microsoft Edge 146.0.3856.109

[√] Network resources [369ms]
    • All expected network resources are available.

! Doctor found issues in 1 category.

[mbcorona]

The reporter identifies this as a regression introduced after 5f58b37, impacting touchscreen coordinate mapping on Windows ARM64. The offset is reportedly reproducible on the default template.

Routing to team-windows for hardware-specific reproduction and investigation of pointer event handling.

[loic-sharma]

Hello @dkmcgowan, could you run git bisect to find the exact commit that introduced this bug? Thanks in advance for your help!

How to use git bisect…

1. Start the bisect session

First, you need to find two commits:

1. A "bad" commit: A commit where the bug is happening (e.g., the latest commit on master).
2. A "good" commit: An older commit where you know the bug did not exist. You can use a version tag (e.g., 3.35.0).

Once you have your "good" and "bad" commit SHAs, start the bisect session:

# Start the bisect
git bisect start

# Mark the commit that is known to reproduce the bug
# (Replace <bad-commit-hash> with the actual SHA or tag)
git bisect bad <bad-commit-hash>

# Mark the older commit that is known to work as expected
# (Replace <good-commit-hash> with the actual SHA or tag)
git bisect good <good-commit-hash>

2. Test the commits

Git will check out a commit halfway between your "good" and "bad" commits. Check if the bug is present in this new, checked-out commit.

If the bug is still present, tell Git this commit is "bad":

git bisect bad

If the bug is gone, tell Git this commit is “good”:

git bisect good

3. Repeat

Git will repeat the process, checking out another commit and narrowing down the search range. Keep testing and running git bisect bad or git bisect good until Git tells you it's found the “first bad commit”.

4. Clean up

Once you’re finished, exit the bisect session:

git bisect reset

Please paste the final message (the one that identifies the "first bad commit") here. That will help us fix this much faster. Thanks!