Facebook not showing YouTube videos thumbnails

Hi,

When I putting YouTube video link on my Facebook page. Video thumbnail doesn’t show up on Facebook. Sometimes it shows sometimes not. During my search & research process I got two workarounds

1. This is a lengthy process but generate thumbnail for my this video
1. Login Facebook and YouTube
2. Select video to share and click share button below video
3. Copy long link, paste in Facebook link
4. Click on attach and post video
5. Facebook will not generate thumbnail, delete post
6. From YouTube this time copy short link
7. Paste in Facebook and post
8. Hopefully it will generate thumbnail (it works for me, but not always)
2. This I got from Google support forum it works for this video
1. Just add &feature=related In last of YouTube link

Thanks