I also use NZXT CAM, and it bitches about Fusion some times. That gets a bit tricky when you want both of them to autorun at startup. I found out through trial and error they can both co-exist, but the order of startup matters. Fusion for me won't even start while the other is running already. In my own personal setup, Fusion conflicts with G.Skill's RGB software. So it's possible Armory will detect your gpu and let you control the RGB. Have you checked to see if Armory Crate alone detects your gpu? While the whole RGB controller software situation is still absurd, a lot of these vendors use the same libraries to detect RGB devices, even if it's not manufactured by said vendor. Maybe the order of installation will sort things out for you? Try uninstalling Armory Crate or any other RGB controlling software including RGB Fusion itself. Fusion is notorious for not playing well with others. But if RGB/LCD is still dead or no longer able to be controlled, you are going to have to uninstall all RGB apps (Armory crate, LConnect, Mystify etc.) from your PC, uninstall nvidia display drivers, restart and clean install latest nvidia drivers, then install Aorus Engine and let it install RGB Fusion when it offers. If I were to guess, I'd say you've got some other RGB software installed that conflicts with RGB Fusion. Doesn't surprise me it doesn't, because Gigabyte's software is crap. Yeah, your Gigabyte device is supposed to show up on the left.

Gigabyte rgb fusion driver