The rear arm of the RM (the bit the cable is attached to), is too close to the adapted cassette at points of the range, (specifically 28T -> 24T) the chain is touching it when trying to shift up so the shift is broken. (I can do a double shift then back if I have to).
It looks to me like pushing all the cogs outwards one level is simply compromising the clearance. It's nowt to do with set screws or the B screw, the TRex itself works fine as does shifting at each end of the cassette.
RM is M786. Cassette is a 11-36 (17T removed IIRC) with a Hope TRex (40t). Shifter is XTR. Hanger and frame are true.
what am I doing wrong?