In my experience the sliders work until the scripting takes over. I call it MAGIC mode. It happens on both defense and offense but is more noticeable when playing defense. When it kicks in there is nothing you can do but wait it out. Rarely happens on Freshmen level but happens more often and last longer as you go up in levels.
This goes back to the older NCAA games and I believe Madden but not sure as I gave up on Madan years ago. Why do they do this? Not sure but I think it is because it is much easier, and cheaper, for them use scripting then to make the AI smarter as you move up in difficulty.