A few posts above there was a discussion about whether Robert Lewandowski departure had an impact. Of course, every departure has an impact for a team. That is also the case at work. When someone leaves the job we do not find a 1:1 replacement. But I do not think that is the question or the problem here. The problem is in the defence. They lost because goals were scored against them. So the focus from Bayern should be the defence.
It's been busy the last few weeks when Mane left and was replaced by Mane but it was a natural thing because, as you said, every departure, especially for a player who has always been the focus of a club, will definitely have an impact and maybe with Bayern's current condition it's not impossible. some will think that this was the wrong decision to sell Lewandowski.