Created attachment 158497 [details]
Screen capture of the buggy window preview positions, and the reproduction

SUMMARY
When the Task Manager panel applet is showing window previews one after the other, their vertical positioning does not correspond to their size, instead, the size of the previously shown preview is used to position the current one. This is a problem when one of the previews has media controls at the bottom, and the other does not.

STEPS TO REPRODUCE
1. Open two windows, one with media controls, one without
2. Move the mouse over their Task Manager entries, each time moving the mouse off the panel and back on - not switching directly from one window entry to the other
3. Do this with one of the windows a couple times, then with the other, than back and forth

OBSERVED RESULT
The vertical positioning of the window preview is wrong exactly once after switching to the other preview, or back.

EXPECTED RESULT
The vertical positioning of the window preview is always correct.

SOFTWARE/OS VERSIONS
Operating System: Fedora Linux 38
KDE Plasma Version: 5.27.4
KDE Frameworks Version: 5.105.0
Qt Version: 5.15.9
Kernel Version: 6.2.12-300.fc38.x86_64 (64-bit)
Graphics Platform: Wayland

ADDITIONAL INFORMATION
Too many times have I adjusted the volume of a video playing in Firefox because of this, when I only wanted to switch to the window playing it...