I would have to assume that some better quality coaching, and a more stable, solid O-line played a huge role in Nix' turnaround. Nix showed flashes of being a big time QB during the 2021 season. He had a stretch of 2-3 games when I even heard one analyst say if he continued that level of play, he would get some Heisman love. One of those games was against Arkansas on the road.
But the play calling, and a horrible O-line had him running for his life way too much. On top of that, and this is where I believe coaching came in, he was just flat out wildly inaccurate. On all throws. I don't know enough about QB mechanics to tell somebody how to fix it. But apparently, someone at Oregon did.