To be honest in this case Nagelsmann is still good enough for a coach but the scheme he plays is always the same and it is clear when he has met many times and has experienced this the other team will get a glimmer of hope because his scheme has been read and it has been proven in the last few matches.
If indeed he still wants to be at Bayern he obviously needs more effort in this regard because otherwise the word "failed coach" will be repeated and he will have to leave even before his contract expires.
If he can make Bayern win the Bundesliga last season,means he still is a good coach who just needs to change tactics from the present one he uses,if the one he uses currently is no longer working,he also needs to check what the problem really is and how to address it.One Quality of a good coach is the ability to change formation,tactics and method of play, if the former is becoming easy for your opponents to access.Changing tactics will enable them play in a way that the opponents will find it difficult to read.He should still be giving more time to change formations and see whether it would work for him or not.
The problem now is trust, we know with the current conditions it is clear that the trust in Nagelsmann has decreased a bit whether it is from club officials or fans so that he cannot sit quietly now.
It would be great if he could change tactics, but at the moment it is a bit difficult because while they are still like this it is clear that stories like Tuchel or Tedesco will repeat themselves in Nagelsmann.