codepen link and iframe embedding

Hello,

I am having new problems with embedding codepen.io content in rise. The embedding worked well in the past, but now just putting a codepen link doesn't load anything. A link like:

https://codepen.io/instructionalist/pen/XEOwBp

results in a blank frame. 

An iframe embed (sanitized per https://articulate.com/support/article/Rise-How-to-Fix-Invalid-Embed-Code) doesn't work either. Here is the iframe code I tried:

<iframe height="265" scrolling="no" title="rgb color sliders" src="//codepen.io/instructionalist/embed/XEOwBp/?height=265&theme-id=0&default-tab=result&embed-version=2" frameborder="no" allowtransparency="true" allowfullscreen="true" style="width: 100%;"></iframe>

This iframe results in a way too long block (though adjusting the height does change the height of the embed, but the units are definitely not pixels). Also the embed is blank.

Any help would be greatly appreciated.