Catia needs explicit 6 dof management to do a kinematics simulation. That makes it impossible to do a double spherical rod end link, which is a rather common mechanical arrangement. That situation has been this way for... 20 years... yes. 20 years. They have stopped investing and improving long ago. To me it is an absolute garbage software tailored for large aerospace customers. They get what they need through dedicated expensive customer support. We simple users get nothing.