I'm looking a bit at Manjaro 20.0, with Gnome, and when I first ran, saw in the top right (system tray?) a coffee cup symbol.  I believe that this means that the Caffeine-ng program might have been running.  I have not seen the coffee cup symbol since.  I tried to click on the Caffeine icon, and also the Caffeine Preferences icon, but seems like nothing happened. I tried searching the Manjaro forums and have not found a solution. Any thoughts? (Sent it to the WLUG, maybe Forrest or another Manjaro user will see it ) Ron