nThis is a known issue/limitation with penalty based contacts and rotational modes. It occurs when the two surface contacting are not parallel/normal to each other. To fix this you can change the formulation to MPC, or try and control the mesh such that all surfaces have equal elements that are normal for each pair of elements.nUnfortunately there currently is no other solution, and sometimes MPC contact is not an acceptable formulation, which means you can be stuck with defeaturing your model to ensure the contact faces are normal to each other. n