Video loading on top of other layers

I am pulling in a vimeo video into a symbol, in which i have a "CLOSE" button that hides the symbol onclick which is on the top layer.

The problem i am having is when the video loads in - it covers my close button - as if it somehow is defaulting to the top most layer?

seems to be only happening in Safari.

Any thoughts?

I am using this code to append a video:

var vimeovid = $("<iframe/>");

sym.$("btn5_video").append(vimeovid);

thanks!