This is something that is still very debatable, because a curse cannot be proven in any way. As you said, Bayern Munich's failure was because they couldn't match the performance shown by Leverkusen this season, so they couldn't defend the championship title they had dominated for seasons.
Harry Kane is still very good, he is even the top scorer now, is it possible that a player who scores that many goals is the cause of Bayern Munich's failure? I think that is unacceptable by common sense.
This was just bad luck, because when he moved to Bayern Munich there was a team that could show something extraordinary like Leverkusen. so that made him fail to get a trophy again in his career.
So far Harry Kane is still 0 trophies while playing with Tottenham and also Bayern Munich, maybe it is very natural to say a lot people if Harry Kane has a curse of zero trophies on every team that recruits him, because so far we can see how Kane have good performance in helping his team win but instead they always fail tobe champions even when Tottenham is one step away from winning the Champions league in 2019 and the Premier League in 2017, what happened to Tottenham may have happened to Munich this season, but of course we can't say if it's the impact of Kane's curse, right as you said, at the moment maybe Kane came to Munich at the wrong time and of course Kane arrival along with the rise of Leverkusen this season so makes the curse rumors even stronger.
I think we can't convict Kane too soon at the moment, because after all Bayern Munich still have a chance to win the Champions League this season, besides of course we will see how Munich next season whether they can rise or even fall back, I think next season Kane has the opportunity to break the curse issue by bringing Munich to be able to win trophies, Because if not, of course, the issue of cursed Kane will continue to be the talk of fans.