Can anyone please help me?

I am having issues getting a perfect panorama. My equipment is Nikon D200, Sigma 8mm F4, Nodal ninja 3, NN Ez leveller II, Panoweaver Pro 6 on a iMac.

I am taking 6 images to make my 360 tour, but can never seem to get a perfect stitch , can anyone help?

The NN3 is setup as recommended Lower rail - 60 Upper rail - 83.