How to reproduce:
1. Open the attached “IN-92001.zip” project
2. Navigate to File → Build Profiles
3. Select “Windows, Mac, Linux” platform and click the “Build“ button
4. Open Steam and navigate to “Add a Game” → “Add a Non-Steam Game…” → “Browse…“ and select the “Input_System_Duplicate.exe“
5. Go to the Steam “Library” page and locate the “Input_System_Duplicate” game
6. Right-click the game, select Properties → Controller, and set “Override for Input_System_Duplicate” to “Enable Steam Input”
7. Press the “Play” button
8. Press the “X“ button on the Xbox 360 Wireless controller

Expected result: One player is added to the game
Actual result: Two players are added to the game

Reproducible in: 1.9.0 - 1.14.0 (6000.0.18f1), 1.14.1 (2022.3.65f1, 6000.0.18f1, 6000.0.54f1, 6000.1.12f1, 6000.2.0b10, 6000.3.0a2)

Reproducible on: Windows 11 Pro (23H2), Windows 11 Enterprise (24H2)
Not reproducible on: No other environments tested

Notes:
- To reproduce, an Xbox 360 Wireless controller, an official wireless adapter for Windows, and a Steam account are required
- Debugging shows duplicate OnEvent messages from XInputControllerWindows and XInputControllerWindows1, leading to the Unity Input System treating them as separate devices
- Not reproducible on Xbox One Wireless controller