Νίκος, calm down. The reason you lose a star is because you are playing in a better league. It's like the difference between the Premier League and the Championship in England and the Greek Super League and Division 1 etc.. There is a massive difference in talent between the 2 leagues and T11 reflect this by amending the star ratings. But as has been said previuosly, it does not mean that your player is a worse player than before, just maybe not as good as the players in the new level.