Created attachment 157253 [details]
White, but correctly shaped icons from Papirus after updating to 5.27.2 on KDE Neon.

SUMMARY
Something causes random categories in system settings to show up as correctly shaped, but completely white when using a custom icon theme after updating from 5.27.0 to 5.27.2. 

STEPS TO REPRODUCE
1. Install KDE Neon 5.27
2. Get New Icons from system settings or apt (e.g. Papirus)
3. Apply new icons
4. Update from 5.27.0 to 5.27.2 on KDE Neon
5. Open system settings

OBSERVED RESULT
After the update to 5.27.2, various category icons show up as the correct shape, just completely white.

EXPECTED RESULT
The category icons should look "normal" meaning they have full color after the update.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: KDE neon 5.27
KDE Plasma Version: 5.27.2
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8
Kernel Version: 5.15.0-67-generic (64-bit) or 5.19.0-35-generic (64-bit)
Graphics Platform: Wayland or Xorg

ADDITIONAL INFORMATION
Tested first on Aspire A515-43 laptop and reproduced in Virtual Machine Manager.
Appears to be something wrong with KDE Neon/KDE Plasma as the icon theme works perfectly fine before the update.
Icon themes tested: Papirus & Tela Dark