Manual Transmission - wtf is wrong with my tranny

Sooooo was cruising at 75 on the toll road today and went to down shift out of 6th and it was stuck.. Finally got it out and seems like it's having issues with getting stuck in 5th and sixth.. The tranny is a stage 2 rebuild with a new slave.. Car has an ls6 clutch that had plenty of life left when we REinstalled it.. Have noticed If im ripping it that by the time I get to fourth the clutch pedal sometimes sticks.. Could this be the master failing or am I looking at a more serious issue? 1-4 are fine as well as reverse..

It might be worth doing a system bleed. Otherwise, you may have a bent 5/6 fork.

ok now it sticks in 6th even with the car off.. Def. feels like there is something binding up.. However.. No grinding..

That reall points to a linkage/ fork concern. It should not grind with the engine off( no rotation).