Hey @thejuniperstudio ,
Checking this out again and I was thinking that this was strange because like I had said before, in the dedicated embed field this wasn't output correctly in my test project.
The issue here is that the link you are using isn't valid oembed spec, which is required for both the rich text editor embed field and the dedicated embed field.
You can verify this with this omebed checker:
https://iframely.com/embed/https%3A%2F%2Fwidget.spreaker.com%2Fplayer%3Fshow_id%3D4308703%26theme%3Dlight%26autoplay%3Dfalse%26playlist%3Dshow%26cover_image_url%3Dhttps%3A%2F%2Fd1bm3dmew779uf.cloudfront.net%2Fcover%2F91e6dbb7b85cf2d52cca69a35c589aa9.jpg
So the only solution here is to follow the Custom embed or HTML code article that I suggested previously.
Thanks