Cloud Reco find the the trackable name but new status is NOT_FOUND

Hello,

I have a cloud data base, and set up the scene (including all keys) as described here: https://library.vuforia.com/content/vuforia-library/en/articles/Solution/How-To-Implement-Cloud-Reco.html#unity

But the thing is that the 3D objects (that are childs of the ImageTarget) don't show up., and the camera isn't tracking the target.

with addition of this code:

private TrackableBehaviour mTrackableBehaviour;

public void OnTrackableStateChanged(TrackableBehaviour.Status previousStatus, TrackableBehaviour.Status newStatus)
{
     print(mTrackableBehaviour.TrackableName);

     print(previousStatus);
     print(newStatus);
}

void Start()
{
     mTrackableBehaviour = GetComponent<TrackableBehaviour>();

     if (mTrackableBehaviour)
     {
         mTrackableBehaviour.RegisterTrackableEventHandler(this);
     }
}

I find that it does find the object (mTrackableBehaviour.TrackableName shows the right name), but newStatus is NOT_FOUND.

How can I solve this?