There is a difference when they play in the Bundesliga and when they play in the Champions League. Their game in the Champions League was more promising, so they managed to advance to the final match after beating Paris Saint Germain in the semi-final match. It was something that was not predicted beforehand, but they managed to do well.
Manchester United in the Champions League this season is very bad, they are the team at the bottom with only collecting 4 points. Even though previously they were favorites to qualify for the round of 16, they couldn't do it. They could only win 1 time and draw 1 time, and 4 other matches ended in defeat. Obviously it's a bad result to be in a group that tends to be easy in my opinion.
Usually until towards the end of the season most teams don't get to put in much efforts in their domestic league as they do in the champions league or other European leagues where they play, this is probably because they prioritize the champions league and other European league much More than their domestic league because in their domestic league, there's always a way to get back to position at some point but with the champions league and Europa it's different.
Champions league performance is usually different with most teams and same applies to their Europa performance too most times and you cannot really get to blame these teams because the prestige attached to these leagues varies aswell a d so they treat it as such, in the Europa the performance of most teams aswell do Barry from their performance in their domestic league , Roma was having a much better performance in the Europa than they were in their domestic league until they crashed out the. They got to improve their performance at domestic levels.
Manchester united aswell did almost same with the champions league, so it becomes like a norm around all other teams in the European competition, this season it was after most of the teams have lost out of the champions league they then get to take their domestic league games serious with hopes of getting to finish their leagues games well by the end of the season so they can have opportunity to appear in the champions league again the following season.