Wacom stylus proximity triggers aggressive snapping only when Ubuntu Tiling Assistant extension is enabled

[perebalazs]

Environment:

• Ubuntu 26.04
• GNOME 50
• Wayland session
• dual monitor setup
• Wacom tablet/stylus

Description:
I originally reported this issue against Mutter because the behaviour looked like a core Wayland/window management problem. After further testing, the issue appears to be specifically related to Ubuntu’s Tiling Assistant extension.

Normal behaviour:

• window dragging works correctly
• windows can be freely positioned
• snapping behaves normally

Problem:
As soon as the Wacom stylus comes close to the tablet surface (proximity event), window dragging behaviour changes dramatically:

• windows become aggressively snapped/tiled
• especially on the secondary monitor
• windows are strongly attracted toward screen edges
• it becomes difficult or impossible to place windows freely
• windows frequently jump into half-screen tiled states

Important finding:
Disabling the Ubuntu Tiling Assistant extension completely resolves the issue.

With the extension disabled:

• Wacom stylus works normally
• no aggressive snapping occurs
• window dragging behaves correctly on both monitors

Additional notes:

• disabling Mutter edge tiling alone does NOT solve the issue:
  gsettings set org.gnome.mutter edge-tiling false
• the issue seems specifically related to the extension’s handling of pointer/stylus drag events under Wayland
• the issue is reproducible consistently

This suggests the problem is likely inside the extension rather than Mutter core or the Wacom driver itself.