Empty notification
Plugged in a PS4 controller that was a bit low on battery, and got an empty notification bubble:
$ upower -m --monitor-detail
Monitoring activity from the power daemon. Press Ctrl+C to cancel.
[15:43:33.418] device added: /org/freedesktop/UPower/devices/gaming_input_sony_controller_battery_a4o53o85o40of4o94
native-path: sony_controller_battery_a4:53:85:40:f4:94
model: Sony Interactive Entertainment Wireless Controller
serial: a4:53:85:40:f4:94
power supply: no
updated: Sat 10 Apr 2021 15:43:33 CEST (0 seconds ago)
has history: yes
has statistics: yes
gaming-input
rechargeable: yes
warning-level: low
percentage: 5%
icon-name: 'battery-caution-symbolic'
History (charge):
1618062213 0.000 unknown
1618062160 5.000 charging
History (rate):
1618062213 0.000 unknown
gnome-settings-daemon-40.0-1.fc34.x86_64