I definitely think JG just doesn't have great in-game instincts. As a pure pocket passer, he's excellent. He's highly accurate and can throw the deep ball with precision. That's part of the reason why he always looks like the best QB in practice and looks great at camps. Case in point, even during that Georgia game, he made 2 spectacular TD throws to Josh Palmer that a lot of SEC QBs could not make.
But when defenses throw things at him that he doesn't expect, he's very slow to react. It's not even that he "panics"; he just doesn't adapt, and makes slow decisions. JG's the rare QB who turns the ball over via inaction (taking too long to decide anything) rather than action (forcing a pass that he shouldn't).
He's almost the opposite of Josh Dobbs in that sense. Dobbs struggled with passing accuracy / precision at times, but often made up for it, by having such superb field vision and great instincts for the game.
I'm not really one of the people on this board who just likes to trash JG. Frankly, he's still been the best QB we've had on the roster that past few years. But I think his lack of instincts for the game have created a hard ceiling for him. You can be the best passer in the world, but if you can't adapt quickly to new information, you'll never be an elite QB. And that's ultimately what's so frustrating about him. He's fundamentally one of the best QBs in the SEC, but has some of the worst in-game instincts.
At this point, I really want to see more of Maurer or Bailey, because even if they don't pass as precisely during practice, I think both of them have very good football instincts. They'll get better with the fundamentals and playbook over time, hopefully. But I think this is "the ceiling" for JG. The parts of the game he still struggles with are the parts that can't really be taught.