I have an XT M786 rear mech with a 3 x 10 setup. When shifting between rear sprockets the chain doesn’t always sit in the new sprocket during the first half a rotation after the shift. The rivets in the chain end up lining up with teeth on the sprocket. Then as a full rotation is completed the chain drops into place with a clunk.

Once fully engaged there are no issues. Its just the noise whilst shifting etc.

I have adjusted the B tension screw to set 5mm between the jockey wheel teeth and largest rear sprocket and the issue is the same with and without the clutch engaged.

Any ideas what could cause this?