I would suggest setting the height and width of the iframe to something visible for a few minutes and opening your profile and seeing what happens. That way, you can see if your YouTube is getting an error, if the video isn't loading, etc. I don't know if you use a VPN but that regularly causes videos to not load because of an IP check that you obviously can't take part in if the iframe is hidden. Though for the record it does work for me on your profile