Hey @Voc007 It looks like it is possible that those wall separations are located on one side of the part so it is possible that there is something going on with cooling or bed level. I would say to check the cooling first and from there we may want to take a few measurements. Do you happen to have calipers that you could use to measure out the wall thickness of the separated area and the opposite side? We may find that both walls are the same thickness or something that could point us in the right direction.