Viostream video embed code in Storyline

Hello folks, 

Does anyone have an embed code (iframe) - particularly from Viostream - that works in the Storyline embed code panel?  Having no end of trouble getting an embed code that will display in Preview, Publish mode and also on our LMS.

The two I've used fail consistently.

<div style="padding-bottom:56.25%;position:relative;display:block;width:960"><iframe width="960" height="540" src="//play.viostream.com/iframe/nixx79jrjdxtnt" referrerpolicy="strict-origin-when-cross-origin" allow="autoplay; encrypted-media; picture-in-picture" allowfullscreen="" frameborder="0" style="position:absolute; top:0; left: 0"></iframe></div>

<iframe width="960" height="540" title="Create a report from existing data" alt="Create a report from existing data - instructional video" src="
https://publish.viostream.com/play/nixx79jrjdxtnt"></iframe>

I have a case with the support team, thought I could ask here too.

Sam K