It's my first day of new seasons in level 3 today. When I opened the game, all my players star is deducted 1 star less. That means my 3 star players charged to 2 stars, and 2 stars changed to 1 star.
How could it fix? Thx
You can't, their quality remains the same however as you are facing tougher opponents and there are better players available in the market they lose a star.