Autoplay not working

I can’t seem to get YouTube and Vimeo videos to autoplay in the lightbox popup using the Swipebox effect.

I have searched for and found this old support thread on the issue: https://www.ads-software.com/support/topic/wheres-video-auto-play

However the instructions mentioned there don’t seem to work.

Vimeo embeds only work for me using the “share” link (i.e. https://vimeo.com/#########). When I add ?autoplay=1 to that link the video fails to load in the lightbox at all and I get a blank darkened screen.

I’m thinking that I need to use the src link from the full iframe embed script (i.e. https://player.vimeo.com/video/#########?autoplay=1) but when I try that link, the video fails to load and I get a messages that says “Opps! The embed code for this video is not valid.”