OnCollisionStay only detects collisions after a secondary collision

The collisions are between a mesh collider and a terrain collider. Box colliders seem to work as expected.

 bool quake = false;
 
 void OnGUI (){
     if (GUI.Button (new Rect(10,35,200,20), "Earthquake")){
         quake= !quake;
     }
 }
 
    void OnCollisionStay(Collision collisionInfo) {
     if(quake){
         foreach (ContactPoint contact in collisionInfo.contacts) {
             Debug.Log(contact.otherCollider.name);
             contact.otherCollider.attachedRigidbody.AddForce(Vector3.up*10);
         }
     }
 }