Youtube related videos impossible to get turn off

Hello,

I'm adding the youtube videos using the "Select media" > "Upload Oembed" > "oEmbed code" and there I put the youtube url with ?rel=0 at the end but the related videos still show up.

I need to be able to add youtube videos without the related videos since they show my competitors video.

My site is: http://maicolcortez.com/

Please let me know how can I achieve this?

P.S. I know that using the iframe code I can turn off related videos but I'm talking about the uploading the video using en oEmbed code in your theme...