When i try to rotate the hand bone in the z axis in the rest pose (of the bone itself) it works as usual, but i setup some copy rotation constraints that are attached to each twist bone from the hand to the last twist bone, and each twist bone is parented to the forearm, because if they are parented as a chain to each other, the copy rotation constraints don't work properly and a dependency cycle comes out, which was caused by the parenting, so they cant be parented to each other like a chain, they must be separated from each other but parented to the forearm like i did...
So if i try rotating the y axis of the hand bone to get the arm twist bones to work and then later try to rotate the z axis down or up of that hand bone, the rotation doesn't go right, the z rotation affects the y causing to rotate both axis with no reason, this issue doesn't happen with the x axis, the x axis is working as it as it should, but not the z axis, i checked that the rotation mode is quartenion in all bones, i attempted with euler mode but i get gimbal locks...
here is the simple ik arm setup if you want to check the issue...please upvoting this post and giving answers are appreciated, thanks.
Michael.