SUMMARY
The power management service no longer shows notifications about low battery or critical battery levers.  It also fails to take the action set for critical level.  In my case, I have low level set to 20%, critical set to 10%, & critical action set to hibernate.

This has worked fine for years, but stopped working about a week ago.  I tried changing some settings & notifications & saving them, but the problem persists.  No log messages from powerdevil are shown in journalctl at these times either.

STEPS TO REPRODUCE
1. Let the battery drain down.
2. 
3. 

OBSERVED RESULT
No notifications or critical actions as stated above.

EXPECTED RESULT
Notification should be shown at or below the low battery level, & the critical battery level.  Action should be taken at critical level.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Arch Linux
(available in About System)
KDE Plasma Version: 5.16.1
KDE Frameworks Version: 5.59.0
Qt Version: 5.12.4

ADDITIONAL INFORMATION