Sadio Mane had a bad performance this season and especially in the last few weeks, I think he can't prove his skills there maybe because of not having enough focus in Bayern Munich since he joined this team. But he is also under pressure because they ask him to have better performance and that's why he can't have enough focus this is one reason for Mane to having fights with other players. Maybe he should move the Saudi teams for the next season.
Its not really bad performance from Sadio Mane last season with Bayern Munich during 25 games scored 7 goals and has 5 assists, exactly he was injured and absent for many games make him difficult on the top performance. Sadio Mane have huge pressure exactly arrived there for replacing Robert Lewandowski consistent become top scorer in Bundesliga. But not fair with comparison between Sadio Mane and Robert Lewandowski because Mane is not as real central forward and he most likely play as winger position.
I think Sadio Mane can back to the top perform next season if Tuchel put him on left winger side than push as center forward, Mane will create many assists like did with Liverpool and how his contribution make Firmino and Salah scoring many goals. Need change with Mane position and Bayern have to sign or find new center forward next season.