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.
The Bayern Munich party who chose to sell Lewandowski was not a unilateral decision from his team, but also the decision of Lewandowski himself who no longer wanted to stay at Bayern Munich for this season. So the deal to sell him to Barcelona is a good thing and it's not wrong at all because Bayern Munich can still get good results this season if they are able to play consistently in every game they have left.