How to Fix Mouse Cursor Misalignment and Scaling Issues in Proton on Wayland

When running Windows games on Linux using Steam Proton under a Wayland display compositor with fractional scaling enabled (e.g., 125%, 150%, or 175% on 1440p or 4K displays), gamers frequently experience severe mouse cursor desynchronization. Common symptoms include the mouse pointer clicking several inches away from targeted UI elements, blurry rendering caused by Xwayland software upscale, or failure of the game window to lock and confine the mouse cursor during gameplay.

Step-by-Step Solution

Step 1: Configure Desktop Xwayland Scaling Behavior

In desktop environments like KDE Plasma or GNOME, ensure legacy X11/Xwayland applications handle scaling internally rather than letting the compositor stretch the window buffer:

On KDE Plasma:

1. 1

   Step 1

   Open System Settings > Display & Monitor > Display Configuration.
2. 2

   Step 2

   Under "Legacy Applications (X11)", select "Apply scaling themselves" instead of "Scaled by the system".

On GNOME / Hyprland: For Hyprland users, add explicit zero-scaling rules to your configuration file:

# In hyprland.conf
xwayland {
    force_zero_scaling = true
}

Step 2: Enable Native Wayland Driver in Proton GE / Proton Experimental

Starting with Wine 9.0 and modern Proton builds (GE-Proton 9+ or Proton Experimental), games can bypass Xwayland entirely and run using native Wayland window surfaces, eliminating cursor offsets:

Open Steam > Game Properties > Launch Options and enter the following environment flags:

# Enable experimental native Wayland driver in Proton GE 9+ / Wine 9.0+:
PROTON_ENABLE_WAYLAND=1 %command%

# Optional: Unset DISPLAY to prevent fallback to Xwayland sockets:
DISPLAY= PROTON_ENABLE_WAYLAND=1 %command%

Step 3: Configure Mouse Confinement in Wine Registry (Wineprefix)

If a specific title keeps losing cursor lock when switching between cutscenes and gameplay, enforce hardware mouse warping inside the game's Steam compatdata directory:

# Locate game AppID (example: 1086940 for Baldur's Gate 3)
WINEPREFIX=~/.steam/steam/steamapps/compatdata/1086940/pfx winecfg

In the Graphics tab of winecfg:

1. Check "Automatically capture the mouse in full-screen windows".
2. Uncheck "Allow the window manager to decorate the windows" if window borders interfere.

Alternatively, inject the registry key directly via terminal:

WINEPREFIX=~/.steam/steam/steamapps/compatdata/<APPID>/pfx reg add "HKCU\\Software\\Wine\\DirectInput" /v "MouseWarpOverride" /d "force" /f