G-HUB is utter garbage, but you knew that already
This is basically just a vent post because I doubt it can be fixed, but I have to open G-HUB (manually mind, I cannot get it to autostart when I boot my PC for love nor money), but then in order for profile button assignments to actually function (DPI/sensitivity is fine!), I have to close the app, then open it again.
I cannot believe how atrocious this software is and it's far from the first time I've had issues with it. I guess I should be glad that this is the issue I have because it's relatively easy to work around and not something like the software just refusing to start, which is one I've had before, or taking several minutes to start for absolutely no reason, which is another one.
Logitech, your hardware is great (or at least your mice are, I am using the G502 X atm) but I actively tell people not to buy your stuff because your software is so utterly, utterly abysmal. Sort it out. I know I am not the only one experiencing this kind of thing, and it is affecting your bottom line.