I often get this as well and it happens because the CPU will try to get in a power run formation to cap off the drive, but I don't have as much problem stopping that. The problem is against spread passing due to my AI's inability to cover Inside to Outside routes. They'll frequently get big gains until they are inside the 10, then I just have to stuff their run/quick pass.
The teams that do a solid job of scoring on me deep in my territory are the ones that stay in a spread the entire drive. Can't count how many times I've sent 8 players and a simple read option scores. Drives me insane.