The jump Devers made in 1 year is incredible. Basically playing Double AA, play a few games in Triple AAA, then go to the Majors. Just the Competition between these Leagues is mind boggling. You have to have patience. It's a stinkin learning Process. All I can see at this moment is he is pressing, trying to do too much. He's is basically a Junior in College, everything probably is moving fast for him at the moment. Understandable.
More games, more practice, more game situations, it will slow down for him. Relax, kid is going to be OK.