Trash icon transparent on dock

[Pedro Victor de Brito Cordeiro]

The Trash Can plugin icon shows up normally on the preferences menu but gets transparent when put on the Dock. Happens in any icon theme, any Plank theme ("Default" in the printscreen) and just with the Trash, not with any other plugin.

Plank v0.11.89 with xfwm4 4.14.1-1 on Arch Linux

[DEBUG 12:39:08.370954] [PreferencesWindow:467] Try to add docklet for 'docklet://trash'
[DEBUG 12:39:08.372182] [ItemFactory:395] Created dock item '/home/pedro/.config/plank/dock1/launchers/trash.dockitem' for launcher 'docklet://trash'
[DEBUG 12:39:08.373955] [Preferences:349] Loading preferences from file '/home/pedro/.config/plank/dock1/launchers/trash.dockitem'
[WARN 12:39:08.375120] [TrashDockItem:104] Could not get item count from trash::item-count.
[DEBUG 12:39:08.375297] [DrawingService:90] Could not get file info for ''
[WARN 12:39:08.375509] [TrashDockItem:35] GSettingsSchema 'org.gnome.nautilus.preferences' not found
[CRITICAL 12:39:08.391621] plank_drawing_service_try_get_icon_file: assertion 'name != NULL' failed
[CRITICAL 12:39:08.418537] plank_drawing_service_load_icon_for_scale: assertion 'names != NULL' failed
[WARN 12:39:08.443934] (Items/DockItem.c:1414):plank_dock_item_real_draw_icon: code should not be reached
[WARN 12:39:08.444331] Creating surface took WAY TOO LONG (43ms), enabled downscaling for this cache!
[CRITICAL 12:39:08.462032] plank_drawing_service_load_icon_for_scale: assertion 'names != NULL' failed
[WARN 12:39:08.486860] (Items/DockItem.c:1414):plank_dock_item_real_draw_icon: code should not be reached

X.Org version: 1.20.8
VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Kabini [Radeon HD 8210]
Icon theme: https://aur.archlinux.org/packages/mojave-ct-icon-theme-git/ (but happens with any other icon theme, Adwaita, Moka etc.)
Installed via Arch Linux official community repository.