Mane wasn't comfortable at all with Bayern Munich at a point he received a fine from them because of that. His performance dropped and he is getting annoyed to keep playing in Bundesliga in my opinion. I read weeks ago that he was thinking about moving out of Germany. I think he wants to get back to England and he might move to Saudi Arabia if they offer to him a good reward.
In the case of Mane, the initiator of the breakup can be not only a football player, but also Bayern Munich itself, because I do not think that the history of the fight between Mane and Sane has been forgotten in the club, and as you know, Bayern is quite scrupulous about such reputational and psychological moments and their impact on the microclimate in the team. In principle, we could try to close our eyes to this if Mane was playing well for the club and he brought invaluable help to the team, but on this front, too, everything is not as successful as the Bayern bosses would like.