SUMMARY The video thumbnail on a piece of media playing appears in all the windows of the grouped windows, not just the one in question playing it. STEPS TO REPRODUCE 1. Install 2. Enable media controls 3. Play video OBSERVED RESULT Pic related https://cloud.hockeymikey.com/index.php/s/TfR538RT6fPiXfn EXPECTED RESULT Only one window SOFTWARE/OS VERSIONS Linux/KDE Plasma: (available in About System) KDE Plasma Version: Latest? KDE Frameworks Version: Latest Qt Version: Latest? ADDITIONAL INFORMATION: Appears on Firefox and Waterfox.
This was observed using KDE Neon 18.04 too so it's not unique to Arch or a screw up of my system.
*** This bug has been marked as a duplicate of bug 409980 ***