Protocol error when connecting laptop dock

[Diax170]

Describe the bug
I have a laptop and 2 extra monitors. When I plug the monitors in and disable the laptop's panel (i don't think the latter is really necessary), running Waybar instance or new instances say Error 71 (Protocol error) dispatching to Wayland display and exit with code 1.
When I disable DP-2, Waybar works fine on HDMI-A-1 but enabling DP-2 back makes it crash. But when instead disabling and enabling HDMI-A-1 it works fine then.
Also, this only occurs when the "height" is set in config

To reproduce
Plug your monitors out and back in, I guess. Suspending also works

{
    "height": 30 // any number
}

Expected behaviour
Waybar doesn't crash

Screenshots
If applicable, add screenshots to help explain the problem.

Environment

• Waybar version (waybar --version):
• Installed from (distro package / source / other):
• Compositor and version (Sway, Hyprland, River, …):

Debug output
Run waybar -l debug and paste any relevant output:

[2026-07-15 16:26:49.312] [info] Tray::onAdd - item bus_name=':1.42', category='ApplicationStatus', icon_name='', title=''
[2026-07-15 16:26:49.312] [debug] Tray::onAdd deferred check - checking ignore list
[2026-07-15 16:26:49.312] [debug] Host::checkIgnoreList - checking 3 items against 0 patterns
[2026-07-15 16:26:49.312] [debug]   Checking item: bus_name=':1.33', category='Communications', icon_name='kdeconnectindicatordark', title='KDE Connect Indicator'
[2026-07-15 16:26:49.312] [debug]   Checking item: bus_name=':1.19', category='SystemServices', icon_name='nm-signal-75', title='Network'
[2026-07-15 16:26:49.312] [debug]   Checking item: bus_name=':1.42', category='ApplicationStatus', icon_name='', title=''
[2026-07-15 16:26:49.436] [info] Bar configured (width: 1080, height: 35) for output: HDMI-A-1
[2026-07-15 16:26:49.436] [info] Bar configured (width: 2752, height: 35) for output: DP-2
[2026-07-15 16:26:49.441] [info] Bar configured (width: 2752, height: 35) for output: DP-2
Gdk-Message: 16:26:49.442: Error 71 (Protocol error) dispatching to Wayland display.

Notice how "Bar configured for output DP-2" appears twice

Additional context
dotfiles #4361 #4399

Also, it was earlier mentioned that this is an upstream gtk-layer-shell issue. Perhaps NixOS uses an older version of it? I am on unstable (26.11) btw