a Sphere [Stride.Models] does have a Bounding Sphere, which could be meaningful for checking spatial reations. However, there seems to be a difference between the Model the Entity is created with and the ModelComponent, which it also has. which one is relevant for the Sphere [Stride.Models] and what is actually the difference between them.
also, it seems that both of them are not initialized with the actual radius when the sphere is created (and manual initialization only works for the BoundingSphere [Model]. should this considered to be a bug (thinking that the BoundingSphere is a property that is part of the Model in any case).