It's not rocket science what is going on with the kid (imo) - he was a bit shocked by the pace and physicality of the league, and the fact he has less time on the ball than in the Bundesliga. When combined with the fact that the majority of games so far have not been situations he thrives in (i.e, they have been gritty, physical affairs), he's lost a bit of confidence and now either struggles to make a decision or rushes it and makes the wrong one.
It's natural - lots of players start out like this. Wirtz is doing the exact same thing at Pool, and cost like 2.5 times as much. It's a rare player that comes in and bosses it right from the off - even Modric struggled initially and needed a season as a winger off the left, to adjust.
It will concern me if he's still like this come the end of the season. For now, I hope he just takes his time to adjust.