Solve for the camera fist by tracking objects that are not “moving” in the shot like walls and floors. Then you track the moving object, and since you already have a camera, when you export the moving object it moves relative to the camera.
You can only match the movement of tracked objects in the scene, so you can link your 3D objects to your tracks, but if you try to place them in the scene in any location, they won’t line up. We are not a “full” camera tracker, so much as we solve for certain locations. As long as you solve for the location, you can insert 3D objects.
Try that and let me know if you have any more questions.