Duplicate window buttons with some Gnome-Apps

[yesmanny]

There are duplicate window buttons with some Gnome Apps when maximized, for example Gnome System Monitor or Gnome Logs.

[jonian]

When you first enable the extension all apps that are already opened display duplicate window buttons.
This happens because the extension uses css to hide the buttons from header-bars.

Restart your session or close and reopen the apps.

[yesmanny]

Now I've localized the problem. It's caused by the Ubuntu snap apps. Deinstalling the snap apps and then installing the normal package based app's solved the problem.