You can shift just as well without the clutch and it would be grinding or lurching going into gear from neutral if that was the problem.
Try a 10/30 oil soso565.
Does the 10w-30 is thicker then 10w-40 ?
I ask that because , when the bike is cold ( during 10-15 minutes ) everything is quite smooth and normal .
so I was thinking when the oil get warmer ( thinner ) the noise appear