So apparently there is a minimum clip length for video clips to be added to Track 2.

You can add 1 sec clips to Track 1, but when you try adding the same video clip to track 2 , it doesn't appear.

To workaround this, create a new video project with your 1 sec clip, add in a solid color screenshot and extend the duration of the video by 1 sec.

Save it as a new video.

Now you can add this 2 sec clip to Track 2

Hope this helps any one who has been searching for answers on google