[Round parts not coming out round]

When I bring models into cuts that are round like a cylinder they end up having sides. Most look like a octagon. Am I missing a setting or something?

[Round (elliptic) Build Plate]

I have followed the instructions to set up our Rostock Max machines in CURA. The only thing that I am not seeing is where to make the build plate elliptic. The instructions show it in printer setup but I am not getting that option. Any help would be greatly appreciated.