I think I got excited too soon, after looking closer the artifact was still there after fixing issky , but wasn’t clear from directional light intensity.
I made same setup twice again once with hdribackdrop and once with editorsphere and sky material but there is always artifact with the sphere.
The inner shadow circle here is the artifact but wasn’t clear , its very clear when I turn off directional light
everything is fine with backdrop
Here are the sky material and sphere mesh
it must be some really stupid blunder on my side