Related videos in YouTube should show only from same channel but don’t

At the end of a YouTube video in the lightbox, YouTube should display a selection of videos from the same channel ONLY, when the tag ?rel=0 is added to the URL. In Easy FancyBox, however, the user is shown video choices from any channel.

Code used:
<h2><a href="https://www.youtube.com/watch?v=Hnhpapw_Opw?rel=0">Video: Automated Ultrasonic Cleaning Equipment</a></h2>

Under Media Settings > YouTube, Autodetect is checked.

The video displays in the lightbox perfectly otherwise. However, we cannot use the lightbox across the site for videos until this issue is resolved. We don’t want users to link to a competitor’s video from our video if it can be avoided.

Thank you for your help with this.

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