Facebook social plugin link gone in vertical

Ayub,
That's likely due to the height of the module that's been set. You'd need to increase the height if you want that link to always show. Once you have faces showing, the module can need to grow based on the amount of space provided. If you've set the height too short, the faces will take up more space and hide the link.

Please try increasing the height in the settings, and that should hopefully fix your issue.

Thanks,
Alex