Embedding a Youtube video through the Social hotspot type is one of the more popular ways of using Socispot. There are some instances where these videos wouldn't display properly within Socispot images.
Things to check:
1. Use the Social hotspot type for better compatibility instead of the Custom HTML hotspot type (unless absolutely necessary).
2. Check your URLs - incorrect URLs will cause the hotspot to not work properly, also some Youtube URL formats do not work 100%, please see example below:
In the example above, the first one is the correct format.
The second one looks similiar, but includes a "&feature=youtu.be" suffix that will cause it to not work properly.
The third one is a short URL that does not work as well.