Simplify3D User Forum

I've started experiencing a problem with the top 4 and bottom 4 layers shifting for some reason. I printing with 4 top and 4 bottom layers with 2 perimeter shells. I'm attaching 3 pics of the problem. Everything else looks pretty good except the top and bottom 4. I've tried everything that was mentioned in the Quality Guide with no change. Thx in advance

I would not say that this is about layer shifting.
Your top and bottom layer are just wider than the ones without solid infill. Considering your pictures I would start with reducing the extrusion multipler.