Testing
https://player.simplecast.com/0d75cbd8-adc8-4c7d-9f91-4ace448ff66f
https://aboutpodcasting.simplecast.com/episodes/podcaststructure
<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless src="https://player.simplecast.com/0d75cbd8-adc8-4c7d-9f91-4ace448ff66f?dark=true&hide_share=true"></iframe>
Looks like using the SimpleCast embed code directly is working (as long as the iframe is allowed in the site setting). Where you using a different method @Grayden_Shand ?