Hey I have had the EXACT same problem while advancing my timing... I loosen the screws and it just doesn't go anywhere.
For some reason methinks that the stator plate can kind of get "stuck" i guess in one position.. If you keep trying, maybe give the engine a few taps from a rubber mallet.. it SHOULD eventually want to move.
It honestly seems like random luck when it has moved for me, but once it does it moves really easily. Put a screwdriver in that little notch below one of the holes, then rotate the flywheel until it hits the screwdriver... put pressure on both in the direction you want it to move and it should work eventually.