Perhaps you could try this https://community.xibo.org.uk/t/youtube-playlist/9769
I believe there was some looping issue there, I'd suggest perhaps some reasonable duration on the embedded element and some other content in the same region.
Regarding your current situation ie one embedded widget per video, are those videos start playing at the same time in CMS or in player or both? I don't think it should work like that, I shall investigate it.
Edit: Are you using the embed links in an iframe? ie the code you can get from YouTube (+ autoplay I guess?)
I created a new layout with 3 different videos from YouTube using those iframes and I don't see this issue you've reported ie they play in order not simultaneously.