Created attachment 121985 [details]
Icon in window decrations

SUMMARY

Some icon themes have replace certain app icons with better ones, but menu icon in window decorations doesn't follow that icon themes, thus still shows the ugly version.

STEPS TO REPRODUCE
1. Install papirus icon theme and latte-dock
2. Apply papirus icon theme in systemsetting5
3. Check the icon of smplayer in both window decorations and latte-dock

OBSERVED RESULT
Icon in window decorations is still the ugly one.
But task manager in the default panel or latte-dock all follow the icon theme to show a better icon.

EXPECTED RESULT
No matter whether it's icon menu in window descorations, or in the default panel or in latte-dock, all icons should follow the icon theme setting

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

ADDITIONAL INFORMATION