As posted by Fabrizio, Nottingham Forest has parted ways with it's manager Nuno Espirito Santo, these's was a tense situation at the club between him and them, I believe that's the main reason why he was sacked. Nottingham Forest has started off this season with a win, a draw and a lose in three matches. I believe that's one of the major trigger as to why he and the club management has fallen off and it resulted in a sack.
When the coach and owner no longer have chemistry between them, of course it will make their relationship crack and ultimately affect the club performance even though Nuno Espírito Santo is a coach who has made a big contribution to Nottingham Forest saving this team from relegation in the 2023 season and giving a Europa League ticket for the first time this season. I think the club owner might regret it because it is difficult to get a coach who is truly suitable because Nottingham Forest is not a big club and does not have many star players so not all coaches can handle an ordinary team to face competition in the Premier League.
Must their be a chemistry between the manager of a team and the owners before they can both work in peace and harmony? No if you ask me, what's important is everyone doing their job professionally without interference from anyone, just do your job professionally, get paid and go home, everyone must not be your friend simple.
As for this sacking by Nottingham forest, I don't think it's a wise idea because he is not doing badly at the club when compared to most manager and it's a decision they might seriously regret it care is not taken.