Created attachment 135385 [details]
video showing observed result

When you open the system tray (the little up arrow) and choose a applet (e.g notifications or clipboard), clicking on the left arrow to go back triggers a sliding down animation but once it switches to the "general" system tray page the animation is canceled causing a weird effect. 

STEPS TO REPRODUCE
1. open system tray (little up arrow).
2. choose a applet (e.g notifications or clipboard).
3. go back to the general system tray page.

OBSERVED RESULT
sliding animation begins but is quickly canceled.

EXPECTED RESULT
do not start any animation.

SOFTWARE/OS VERSIONS
Linux: openSUSE Tumbleweed
(available in About System)
KDE Plasma Version: 5.20.5
KDE Frameworks Version: 5.78.0
Qt Version: 5.15.2