Created attachment 138576 [details]
System Settings > Users: avatar not displayed

SUMMARY
In "System Settings > Users" the user avatar disappeared (see attached images). If I click the "Change Avatar" button (that is no longer visible) I get a list of empty avatars. Even if I chose an avatar with my initials it is not shown.

Also during log out, the avatar appears as a square, instead of a round image.

I was using Plasma 5.19 (Kubuntu 20.10) and all was fine. Then, after some update I started getting this bug. Then I updated to Kubuntu 21.04 (Plasma 5.21) hoping that it would fix the problem, but it didn't. I'm still getting these avatar glitches.

I am using Nvidia graphics, driver version 460.73.01.

STEPS TO REPRODUCE
1. Go to System Settings > Users
2. The avatar disappeared

OBSERVED RESULT
The avatar is not shown and cannot be changed;

EXPECTED RESULT
The avatar is shown and it is possible to change it.

SOFTWARE/OS VERSIONS
Operating System: Kubuntu 21.04
KDE Plasma Version: 5.21.4
KDE Frameworks Version: 5.80.0
Qt Version: 5.15.2
Kernel Version: 5.11.0-17-generic
OS Type: 64-bit
Graphics Platform: X11
Processors: 16 × AMD Ryzen 7 3700X 8-Core Processor
Memory: 15,6 GiB of RAM
Graphics Processor: GeForce GTX 1660/PCIe/SSE2