I think it is rather the exception than the rule that a team which is performing bad in the domestic league is one of the strongest teams in the Champions League. Yes I know that now some people will come up with examples, like Sevilla and how they won the Europa League last season when they were so bad in La Liga. But where is Sevilla now? They finished their Champions League group with 2 points out of 6 games and got destroyed in almost every game. There is a correlation between the overall performance of a team in the league and the other competitions, but yes there are exceptions of course.
It's hard to say that because we've seen several teams perform extraordinary in the UCL when their performance in their domestic league was very poor, but that only happened to a handful of teams and not forever so we can't draw any conclusions about that, what is certain is that the teams that have Good performance in their domestic league has a much greater percentage or opportunity for them to be able to do the same in the Champions League competition.
I am certainly too lazy to collect any data about that now, but you first said there are several teams with "extraordinary" performance in the UCL while performing very poorly in the domestic league. Then you reduced it to a "handful" of teams. The easiest thing to do would be to provide examples here. Which are all those teams you are talking about? Extraordinary performance in UCL, very poor performance in the domestic league. I admit I can't think of any team at all at the moment. Really the only example that comes to my mind could be Chelsea in the 2020/2021 season when they defeated Manchester City in the final, but it could still be discussed whether their performance in the Premier League could be considered "very poor" that season.
I believe that it rarely happens that a team performs extraordinarily well in the Champions League while playing very poor in the domestic league. There might be some exceptions, but this is nothing I would recall as having happened frequently.