plasma6: fontsettings won't saved

[younker]

upgraded to plasma 6 from 5.27 and I tried to delete all the config files of KDE from ~/.config folder, but when I tried to set the font of the desktop environment, it doesn't reflect the change to any applications, even I reboot the machine.

So what may be wrong from my setup?

[younker]

solved by unmerging qt6ct, then the fontsetting from system settings works without any issue.