Every day and after every game all players lose or gain morale... There are many reasons for that... Some players play bad and lose it, some players play good and get some... Some players play too often, while other players play rarely... League position affects morale... It is simply part of the game... Take a pic of your team morale at the end of the day and then, take one when new day starts, after reset and see for yourself... It's not something added with the last update...