video embed lack

I’m using the plugin on a staging site to display YouTube videos. It works fine on the desktop view, but on both iPhone and iPad it displays a black box instead of the video image. I’m using the BB Cache Helper plugin, and have cleared the cache on my hosting site, and on my mobile browser, but that hasn’t made a difference. I’ve tried both Safari and Chrome. I’ve also deactivated plugins.

It’s behind a privacy password, so if you want to see it or have login access I can provide that in a separate message.

Thanks.