most people also complaining why Bayern management suddently sacked Nagelsmann without any spesific reasons
The reason for Julian Nagelsmann's dismissal is very clear, if you look at various well-known sports media, the reason Bayern Munich sacked Nagelsmann was due to a significant decrease in performance, yes, even though Nagelsmann has so far managed to keep Bayern Munich in the UCL, that's just not enough for Bayern Munchen. FYI, they have won the Bundesliga title since the last 10 seasons, if they don't manage to get the Bundesliga title this season, it will be a big surprise for people.
The performance was so poor not in the champions league but league outings
He is a good coach but the club has taken the decision they feel is best for them
Thomas Tuchel was so quick to accept the deal he must have had big dreams managing Bayern Munich