SUMMARY
On Plasma 5.19 beta, after a while, the closing animation of a panel (K menu, systray...) "blinks" quickly if I click on another window to close the panel. It does not occur right after the session starts, so maybe something triggers the glitch. This is a video of the glitch : https://www.youtube.com/watch?v=hZryHog5axY

I slowed down the effect to make the bug clearer : the first time my mouse pointer stays on the icon and the glitch does not occur. The second time I move it around and then you can see the blink before the animation starts.

STEPS TO REPRODUCE
1. Open several applications
2. Open the K menu or the systray
3. Close the K menu or the systray by clicking a window on the desktop.

OBSERVED RESULT
The closing animation plays, but there is a "blink" effect that should not be here.

EXPECTED RESULT


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION

The glitch is NOT triggered if I close the K menu by clicking its icon. Watch the linked video to see the glitch. The K menu seems more affected by the glitch than the other panel elements.