I read more often in the Schwatzgelb forum, where they've been talking about his body language and his movement up front in general lately. I think Dortmund will be sad to see him go, but maybe they will be better off if they get a striker who is good for the team as a whole.
It's also possible that Haaland is simply tired of Dortmund and its mediocrity and therefore turns on his team-mates. It will be interesting to see how Haaland does in a stronger team with stronger characters.
Haaland had a horrible match on Saturday, and I agree his body language was a bit negative, but Dortmund is definitely a lot better with him than without him:
With Haaland in the Bundeliga and CL this season:
14 games, 9W-1D-4L, 38-25 goal diff.
2,71 goals per 90 scored and 1,78 goals per 90 conceded. 2 points/game - He has scored or assisted 66% of Dortmunds goals while on the pitch in the CL and Bundesliga this season.
Without him:
9 games, 5W-0D-4L, 13-12 goal diff.
1,44 goals per 90 scored and 1,33 goal per 90 conceded. 1,67 points/game (Met 4 of the bottom 5 teams and 2 midtable teams (8th and 10th) in the Bundeliga in this period)
Basically 2 different teams.