YT or Vimeo on Embedded widget in V4

In the latest V4 CMS 4.0.6 on Docker, running on Windows clients R402.1, I’m struggling with a) adding the video to the layout properly, and 2) playing it on the CMS.

I looked at the layouts that still work after my conversion from 3 to 4, but can’t replicate on a new layout. For example, I can use a simple iFrame for YouTube in the HTML box and it works with autoplay, but I can’t find a way in v4 to turn the sound off for the video (or the widget itself). We have multiple videos on the layout and only want one to be heard. The new sections for HTML, Style Sheet, etc. don’t appear to work for me (and the “Copy” button doesn’t appear to work for me).

For Vimeo, I can add the iFrame to the embedded widget HTML box, and the video does play in the Preview, but on the Windows client it shows “Player error. The player is having trouble. We’ll have it backup and running as soon as possible.” I’ve checked and the video plays fine through web browsers on the Windows client, just not through the Xibo client.

Maybe this will be in some updates in 4.1?