HTML outputs extra code with CMS fields

I am trying to add a Spotify player with HTML embed and a CMS field for the Spotify html link. Its working great if I use a static link but when I add the CMS field then there is added some extra html that makes an error (Refused to display ‘’ in a frame because an ancestor violates the following Content Security Policy directive: “frame-ancestors ‘none’”.)
Is it a bug or is there something I have overseen

> **Custom Code**
>     <iframe src=«CMS Field" width="300" height="80" frameborder="0" allowtransparency="true" allow="encrypted-media"></iframe>
> 
> **HTML output on site** 
> 
> <div class="html-embed w-embed w-iframe»>
> <iframe src="https://open.spotify.com/track/6wAsCKZOnTDU2ueWLzNcJD?si=JFp0HC_IS56NPY32Na8F1g" width="300" height="80" frameborder="0" allowtransparency="true" allow="encrypted-media"></iframe></div>
> 
> (This is added:)
> #document
> >     <html>
> >     <head>
> >     </head>
> >     <body>
> >     </body>
> >     </html>
> >     </iframe>

@perkristian - It would be important to see the actual embed code, copied from within the embed. If your post has that already, you will need to clean up the source as this is not valid html.

This is the code that is pasted in to the HTML embed: <iframe src=«CMS Field" width=“300” height=“80” frameborder=“0” allowtransparency=“true” allow=“encrypted-media”></iframe> > >

The iframe source (src) marked “CMS field” is an dynamic html field (cms) with a HTML embed adress provided from Spotify. I made it with static links first and that worked fine then I replaced the static link with the dynamic field then the #document with html, head body gets added to the code and the error shows up in the console.

@perkristian - Please share a read only link and I will take a look for you. You can PM me if you prefer not to share it publicly.