It was fine when I first set it up but now I have to down-click 2 to get it off of the 42t. Cable is new, x9 rear mech, x7 shifter. Can I alter the spring strength of the rear mech?

Any ideas on how to cure it?

I have a similar set up. My old derailleur was just too worn. I’ve just got a new X9 type 2.1 & it’s much better now.

I have the type 2 rear mech. About 8 months old.

Wind the B tension screw in a bit.

I have had various issues shifting back down the cassette and it seems to be all down to the B tension screw – as suggested above.