SUMMARY Icon only task manager does not show window thumbnails STEPS TO REPRODUCE 1. Set "Keep window thumbnails" to "always" in compositor settings 2. Hover cursor over thumbnail OBSERVED RESULT See Application icon EXPECTED RESULT See preview of window SOFTWARE/OS VERSIONS Linux/KDE Plasma: Nixos-Unstable (available in About System) KDE Plasma Version: 5.25.1 KDE Frameworks Version: 5.95.0 Qt Version: 5.15.3 ADDITIONAL INFORMATION Nixos does not have 5.25.1 yet (should have it in one to two days), however, just updating the source and building works fine.
*** This bug has been marked as a duplicate of bug 455231 ***