It's likely a 0.4.3 problem as this new version has neutered some of my pass rushers in several leagues. Your guy has good speed, acceleration, strength and pass rush so idk why he's not getting pressure.
Maybe he's just been faced with elite tackles who don't give up sacks? Have you tried changing defensive plays? Maybe switch him from one side of the defense to the other, or switch personnel around him.
If there is a logical explanation for the lack of pass rush, I'd love to see it.