Mullet drivetrain shifting/ indexing issues

I not too long ago modified to a Mullet drivetrain on my Hakka. Went from a Drive 1x -11sp to a 1x -12sp utilizing XX1 rear derailleur and a 1230 NX cassette. I used the Ratio 12sp equipment for the shifter. All that is mounted on a Chris King hub. The shifting from the shifter has been superb. However I CANNOT appear to get the indexing proper. If I get the shfiting easy for the decrease half of the cassette, it is flawed on the highest half. If I alter the highest half of the cassette, the decrease half just isn’t shifting right. I can not get it to the place the entire cassette/ shifitng is listed accurately. Its nearly unrideable.

I’ve tried a model new der. hanger, new housing/ cable, reinstalled every part, all bolts are tight and seem like lined up accurately. The rear der. was model new when mounted.

The one factor I can consider is that the freehub physique for the king hub is taken into account a 11 velocity. Once I mounted the cassette, it wouldnt tighten all the way in which. So I put a spacer ( 1.85 mm spacer) behind the cassette to make it truly tighten. May this spacer be what’s inflicting the issue? I do know King makes a 12 velocity freehub physique however I did not suppose I wanted it if I used the cassette spacer. Its the one factor left to attempt is get the brand new freehub.

Any thought? Suggestions?