Bayern Munich's performance has been the best in comparison to the other teams in that group. They have a six-point advantage in the group after winning their first two games. There is also no indication that they will lose their next group stage encounter due to their current dominance. They say football is unpredictable, but Bayern Munich's odds of progressing to the next round are nearly 100%, and I don't see anything stopping that from happening now.
Manchester United has lost two games and has four more to play in the group round. If they win all four remaining matches, which I doubt, they will qualify for the next round of the Champions League. Manchester United's form has been inconsistent and many people have lost faith in the club. They are not performing poorly, but in the Champions League, they must put in more effort if they want to go to the next round of the group stage with others.