I read a few at https://www.google.com/search?q=G-Hub+“Downloading”+Keyboard+site:www.reddit.com and came away with no new ideas.
That is, since that research found all the ideas I had, I didn't type in any new answers here on CNET.
My G512 keyboard is showing downloading under the icon for it in G-Hub, so I can’t click on it and customize the lighting. And in settings it shows not connected? Any ideas?