For some reason Man United players are performing way better against stronger teams, but when they play against a weaker team, their performance drops.
I think the major challenge that most Manchester United supporters have with the club currently is that their performance is very inconsistent and games that you expect them to win the end up not winning the game either losing it or picking up just a point. It is going to be very terrible for Manchester United if they continue like that this season considering that other teams have improved significantly including Chelsea with whom they were being compared with last season. Amorim will come under more pressure if he cannot deliver in their next game against newly promoted side Burnley.