SUMMARY
If you open the activity manager (in my case via hotkey leftmeta+escape) the manager window should overlap windows that are placed near the left screen edge. But on wayland (it does not happen with X11) the manager window moves the windows to the right. When closing the manager window the previously moved windows are placed at the left screen edge.

STEPS TO REPRODUCE
1. open a window (I tried it with thunderbird) and place it near the left screen edge (but not touching the screen edge) so that it would be overlapped by the activitiy manager window.
2. open the activity manager
3. close the activity manager

OBSERVED RESULT
In step 2 the thunderbird window is moved to the right (docking to the activity manager window).
In step 3 the thunderbird window is moved to the left screen edge.

EXPECTED RESULT
In step 2 the activity manager window should overlap the thunderbird window without moving it.
In step 3 the activity manager window should be closed with changing the position of the thunderbird window.

SOFTWARE/OS VERSIONS
Operating System: Kubuntu 21.10
KDE Plasma Version: 5.23.3
KDE Frameworks Version: 5.88.0
Qt Version: 5.15.2
Kernel Version: 5.13.0-21-generic (64-bit)