How's your playcalling diversity? I've found the AI is aware enough to key on repeated run styles and repeated plays from formations. I have issues when I constantly press an ISO. This normally happens to me second half when I'm trying to eat clock and fatigue the defense. After a successful inside run, calling the same play again in sussecion will normally (for me) backfire with results like you've described.
I find most success in power running when there is a hint of an outside zone presence. To elaborate- my depth will normally consist of a bruiser that can catch (RB1), a jack of all trades and master of little (RB2), and a bigger back with speed, pass blocking, and catching ability as my 3DRB. Many times untill I find the right personnel with depth, my RB1 and 3DRB are the same. I pound the inside with power plays predominantly (ISO, power, trap, dive, etc), but I will conciously add in: inside zone (this is really meant to cut outside, if the def is keying on ur inside game- a well timed inside zone can yield great chunk plays when u find the cut out), outside zone (think reverse or inside zone. The defense is keying in the inside power, but is aware of the zone taking it outside, outside zone sets up the stretch- but affords the inside cutback that keeps defenses from over playing that outside cuts.
Even plays like a fake FB dive HB pitch. Sub in dual backs, the CPU sees RB1 (power back) at FB- fake dive holds def inside and your RB2 can find room on the edge.
I have had several games where the CPU has stonewalled my running. And several games where it's been almost arcadish. To me it's not about the sliders as much as it is keeping the defense honest.
It makes the games take slightly longer as more time is spent strategizing than is spent quick play calling and quick snapping to get to next play- but for my preference that is perfectly acceptable. There's a reason a 60 minute game takes many hours (I get commercials extend game lol), and a reason teams normally don't hike the ball with 25-30 seconds on the play clock irl.
Idk how you play, and don't mean to insinuate u play any certain way- but hopefully this made some sense and maybe can help you out down the line.