Drag-to-tile stops working after suspend; keyboard shortcuts keep working

Describe the bug

After resuming from suspend, dragging a window to a screen edge or corner no
longer triggers tiling. The preview never appears and the window simply stays
where it is dropped.

Keyboard shortcuts (<Super>Left / <Super>Right) continue to work normally,
so the extension is still running and still handling input — only the
drag/pointer path is dead.

Disabling and re-enabling the extension does not fix it. Logging out and
back in does.

Steps to reproduce

1. Boot, log in, confirm drag-to-tile works.
2. Close the lid (suspend) or lock the screen, then resume.
3. Drag a window to a screen edge.

Expected behaviour

Drag-to-tile works after resume, as it does after a fresh login.

Actual behaviour

No preview, no tiling. Keyboard shortcuts unaffected.

Diagnostics

The extension itself reports as healthy after resume:

$ gnome-extensions info tiling-assistant@ubuntu.com
Version: 54
Enabled: Yes
State: ACTIVE

org.gnome.mutter edge-tiling is false, which is expected — the extension
overrides it and records the original in overridden-settings:

$ gsettings get org.gnome.shell.extensions.tiling-assistant overridden-settings
{'org.gnome.mutter.edge-tiling': <@mb nothing>,
'org.gnome.mutter.keybindings.toggle-tiled-left': <@mb nothing>,
'org.gnome.mutter.keybindings.toggle-tiled-right': <@mb nothing>}

Key data point: with the extension still enabled and in this broken state,
setting org.gnome.mutter edge-tiling true restores Mutter's own drag-to-tile
immediately, and it works correctly. So pointer tracking and drag handling in
Mutter are fine after resume — the failure is confined to the extension's own
drag path.

dconf watch /org/gnome/mutter/ during a lock/unlock cycle shows the expected
override being removed and reapplied (unset → false), i.e. the extension is
correctly re-initialising its settings. It is only the drag behaviour that does
not come back.

The journal contains one possibly related error:

JS ERROR: TypeError: can't access property "get_transition", this.actor is null

System information

• Ubuntu 26.04.1 LTS (clean install)
• Wayland session (26.04 is Wayland-only)
• GNOME Shell 50.1
• Extension: Ubuntu Tiling Assistant (tiling-assistant@ubuntu.com) version 54,
  bundled, no separate deb package
• Hardware: Lenovo ThinkPad X1 2-in-1 Gen 11 (convertible, touchscreen + pen),
  Intel Core Ultra 7 355, kernel 7.0.0-31-generic
• Single internal display, 1920x1200, scaling 100%
• Input: touchpad (also reproducible with TrackPoint)
• suspend-then-hibernate configured; reproducible after plain suspend as well

Possibly related

The convertible aspect may matter: this machine reports SW_TABLET_MODE and has
a working accelerometer, so the shell handles device-mode transitions that a
regular laptop does not. I have not yet isolated whether the trigger is suspend
itself or a tablet-mode transition around it — happy to test that if useful.

No source file, test, or entry point is named in the report. Start by tracing the extension's drag/pointer lifecycle across suspend, resume, lock, and tablet-mode transitions, then inspect the journal error about a null actor. Done means the drag preview and tiling return after resume while keyboard shortcuts continue working.