what value does that key have in it if you run dconf-editor or even gsettings?
[Me@tower20 ~]$ gsettings list-recursively org.gnome.shell.overrides
org.gnome.shell.overrides attach-modal-dialogs true
org.gnome.shell.overrides button-layout 'menu:minimize,maximize,close'
org.gnome.shell.overrides dynamic-workspaces true
org.gnome.shell.overrides edge-tiling true
org.gnome.shell.overrides workspaces-only-on-primary true
The standard arrangement works here. I will try settings the close button on the left and see what happens.
It did work here to set the close box to the left of the title bar.