SUMMARY STEPS TO REPRODUCE 1. Create a vertical dock 2. Set Unity Layout 3. Start different tasks until you fill the taskbar OBSERVED RESULT The entire vertical dock starts to bounce as it tries to get the right size SOFTWARE/OS VERSIONS Linux/KDE Plasma: Neon 18.04 (available in About System) KDE Plasma Version: 5.17.3 KDE Frameworks Version: 5.65 Qt Version: 5.13.2 ADDITIONAL INFORMATION This is an old bug that drive me crazy. I do not use the Unity Layout but my own vertical layout and I've set the scroll to avoid this bouncing thing.
*** This bug has been marked as a duplicate of bug 414180 ***