Theme for gtk apps in KDE Plasma

I had some gtk apps that did not want to theme correctly in KDE Plasma, so this is how I resolved it:

I installed:
$ sudo pacman -S xsettingsd gtk-engines matcha-gtk-theme

Then I setup the xsettingsd configuration:

$ mkdir ~/.config/xsettingsd
$ nano ~/.config/.xsettingsd/xsettings.conf`

Gtk/EnableAnimations 1
Gtk/DecorationLayout "icon:minimize,maximize,close"
Gtk/PrimaryButtonWarpsSlider 0
Gtk/ToolbarStyle 3
Gtk/MenuImages 1
Gtk/ButtonImages 1
Gtk/CursorThemeSize 24
Gtk/CursorThemeName "breeze_cursors"
Net/IconThemeName "breath2-dark"
Net/ThemeName "Matcha-dark-sea"
Gtk/FontName "Noto Sans,  10"

Finally I reinstalled kde-gtk-config to make sure it picks up the optional dependency for xsettingsd:

$ sudo -S kde-gtk-config

I then rebooted, but I suspect a logout would work too. Now apps like pamac-manager theme correctly.

Thanks for your feedback and the tip, same issue with the Odroid C2 kde stable branch, I hope it will be solve with an update.