I have Von Miller with 99 finesse in my cfm, and he almost without fail spins in place with the blocker still directly in front. When the spin should twist him to either the inside or the outside of the blocker to get around.
It's actually much easier for me to get sacks using Derrick Wolfes 89 power bull rush.
Pass rushing in general seems pretty borked. I am playing on All-Madden using Armor & Swords slider set but I have to drop the cpu blocking to about 20 to get roughly the right number of sacks, but I have to put the user pass blocking slider to 8 freking 8 to ever get sacked myself, actually thinking about putting user pass blocking all the way to 0. But I do have really really good tackles so it might about right at 8.
Gonna try editing Miller to remove his spin move trait as an experiment just to see if the swim works better. Might even try taking all his pass rush moves away for a game or two as an experiment as well.
I am thinking the game might be bugged in such a way so that if you were using Nkemdiche yourself instead of cpu you might not get the same results.