The defeat from Bournemouth has shown that currently Manchester United has many weaknesses that they must immediately improve, actually in the match against Manchester City they have shown a good and solid game between lines, but we don't see that when they play against Bournemouth, in addition to consistency, it seems that defense is still the reason why it is easy for the opposing team to scoring in Onana goal, so maybe now Amorim needs to find a right line up Especially in their defense, the transfer market may be an alternative for Amorim to improve his squad, but with the amount of money they has spent previously, that it will not have an impact on their finances if they sign players again in january?
Manchester United performance against Manchester City wasn't good, both of them play very bad, Manchester United was lucky they got 2 big chance in near end of the match. If not, they would lose against Manchester City.
I'd say Manchester United hasn't changed, they only have few good players like Amad, Mainoo, and Mazraoui, other than that, they're the same.