Seasons is a different beast for me. It feels so much fairer. I've had my ass handed to me on it numerous times and just held my hands up to facing a better player.
There's been numerous times in UT where you can just feel the change happen, players stop pressing, defenders step up for an offside trap to leave the opposition striker through (despite having a deep defense set to cover), players boot the ball away in defense when I just want to hold the ball and control possession, 35 yard weak foot shots from 76 rated defenders whistle in, deflections go straight to the opposition, goalkeepers parry a cross into the goal, defenders miscontrol the ball when simply turning to a fullback and let the opposition in... the list goes on.
It's nothing to do with your own skill, it's the AI or mechanics going to shit because it's not the right time for you to win.