Arch Linux

Power Manager's system tray icon doesn't appear in the xfce4-panel. I have tried it with Adwaita and elementary icon themes.

Additional info:
* xfce4-power-manager 4.16.0-3
* upower 0.99.20-1
* xfce4-panel 4.16.4-1
* adwaita-icon-theme 42.0+r1+gc144c3d75-1
* elementary-xfce-icons 0.17-1 (from AUR)

* TRACE[xfpm-xfconf.c:204] xfpm_xfconf_property_changed_cb(): Property modified: /xfce4-power-manager/show-tray-icon

(xfce4-power-manager:26036): xfce4-power-manager-WARNING **: ../panel-plugins/power-manager-plugin/power-manager-button.c:858: invalid property id 2 for "show-panel-label" of type 'GParamInt' in 'PowerManagerButton'

(xfce4-power-manager:26036): xfce4-power-manager-WARNING **: ../panel-plugins/power-manager-plugin/power-manager-button.c:858: invalid property id 3 for "presentation-mode" of type 'GParamBoolean' in 'PowerManagerButton'

(xfce4-power-manager:26036): xfce4-power-manager-WARNING **: ../panel-plugins/power-manager-plugin/power-manager-button.c:858: invalid property id 4 for "show-presentation-indicator" of type 'GParamBoolean' in 'PowerManagerButton'

(xfce4-power-manager:26036): xfce4-power-manager-WARNING **: ../panel-plugins/power-manager-plugin/power-manager-button.c:858: invalid property id 3 for "presentation-mode" of type 'GParamBoolean' in 'PowerManagerButton'
TRACE[xfpm-manager.c:754] xfpm_manager_show_tray_icon(): Showing tray icon
TRACE[../panel-plugins/power-manager-plugin/power-manager-button.c:568] power_manager_button_add_device(): entering for /org/freedesktop/UPower/devices/DisplayDevice
TRACE[../panel-plugins/power-manager-plugin/power-manager-button.c:469] power_manager_button_update_device_icon_and_details(): entering for /org/freedesktop/UPower/devices/DisplayDevice
TRACE[xfpm-power-common.c:226] get_device_icon_name(): icon_suffix -symbolic, icon_base_length 15, upower_icon battery-missing-symbolic
TRACE[xfpm-power-common.c:226] get_device_icon_name(): icon_suffix -symbolic, icon_base_length 15, upower_icon battery-missing-symbolic
TRACE[xfpm-manager.c:727] xfpm_manager_tray_update_icon(): updating icon
TRACE[xfpm-manager.c:711] xfpm_manager_tray_update_tooltip(): updating tooltip


* upower -d
Device: /org/freedesktop/UPower/devices/DisplayDevice
power supply: no
has history: no
has statistics: no
unknown
warning-level: none
percentage: 0%
icon-name: 'battery-missing-symbolic'

* "pacman -Ql xfce4-power-manager" shows:

xfce4-power-manager /usr/share/icons/hicolor/48x48/status/battery-missing.png
xfce4-power-manager /usr/share/icons/hicolor/scalable/status/battery-missing-symbolic.svg
xfce4-power-manager /usr/share/icons/hicolor/scalable/status/battery-missing.svg

Daemon:
daemon-version: 0.99.20
on-battery: no
lid-is-closed: no
lid-is-present: no
critical-action: PowerOff

* https://gitlab.xfce.org/xfce/xfce4-power-manager/-/issues/104

Steps to reproduce:
Open xfce4-power-manager-settings and enable "System tray icon".