I think he's just adjusting to the faster tempo of the game in England. In American football they talk about college quarterbacks having to get the ball away quicker once they get to the NFL and there's a parallel to him adjusting to having less time to make his mind up.
He's talented enough and clever enough that I don't think it'll take long for him. Isak will help too, the way Salah and Gakpo are playing at the moment it seems like teams are focusing all of their defensive plans on stopping Wirtz, having another top player firing might give him a bit more time and space.