Unexpectec 3D Model

Hello everyone

I am trying to develop an app for education. Basically, I want to give two different types of content to students base on their decision. On my app, Scene1 has a 3D model which should appear when the target image detected. Scene2 has a video which should play when students click to button Scene1 and camera recognize to the image. However, due to the video player codes when the app starts the 3D model appears on the screen even before the target image recognizing.

I add just basic codes on DefaultTrackableEventHandler: public UnityEngine.Video.VideoPlayer videoPlayer();

Private trackfound videoPlayer.Play();

Private tracklost videoPlayer.Pause();