Google My Maps iframe doesn't work?

Can someone explain to me why a standard Google My Maps iframe is not being displayed on the published site?
I have tried this on a non dev site with a CMS subscription and custom domain. It also doesn’t work there. I’ve tried it on a standard blank Webflow project and it won’t work there either. Anyone any idea? Tested on Chrome and Safari.

Here is my site Read-Only: [LINK][1]
([how to share your site Read-Only link][2])