Interactive Cloth collider breaks when parented to an object with a rigidbody.

I created a system where the player in my game could tie together objects, and the ropes would be rendered with interactive cloth. Everything works except when I create the cloth at runtime and then parent it to an object that has a rigidbody somewhere up its hierarchy. At that point, the first attached collider simply lets go and one end of the rope falls to the floor.

I tested this by attaching a prebuilt rope to a default unity cube. It works correctly until, during runtime, I add a rigidbody component to it. If the rigidbody is there before runtime, it works fine.

After about 5 hours of testing, I found the solution (which seems to be a bug.) An attached collider without a rigidbody being parented to an object WITH a rigidbody will cause it to break (only during runtime.) The solution is to just add a rigidbody to it.

but how?
kindly clear it