To answer both questions in 1 go
1. My defence came in at average - Medium - Inside and Outside. I am normally Respectable High, sometimes strong low. The rating of the PF does not mean he was my greatest defender, he is an inside defender not an outside defender.
2. This is how I chekced that it had changed, I am totally positive that I did not make that change, I chekced it 30 minutes before the game and it was correct
I was hoping a BB could check into this for me to see what happened
Defense has a strong impact on player ratings. Your PF scored a 16.5 which was far and away the best individual rating of any of your players, so he was your best defender. Period. As for team ratings, there are different factors for why this would change, like lineup, enthusiasm, game shape, tactics used.