Also if you check your finances screens check if any large payments have been made that haven't been in previous seasons. It could be that the club has been forced to spend the money on infrastructure in order to meet the new leagues rules.
For example a lower league club being promoted and having to make the stadium all seater from terraces.
Not sure is things like having certain grades/level of say medical facilities, broadcast facilities are a thing. Going from the English Championship to the English Premier League some teams stadiums don't have the correct level of facilities, clubs are given 2 years in real life to get these up to standard. In real life this was a big thing when Blackpool were promoted to the Prem. Like I said I'm unsure if that is in the game but if it is could also explain where the money has gone.