iFrame not loading using TinyMCE

Good morning,
today I changed the Wysiwyg that comes embedded for TinyMCE just as I used to use on V3, I’m using the same setup for the editor, but for some reason, it’s not loading Iframes as it used to do in V3. Do you think it has something to do with some Strapi thing blocking its connection?

I forgot to mention this problem is happening on Strapi V4

I have the same issue, have you fixed that issue?

Yes, I did.
To solve this you’ll need to overwrite the security middleware.
I did something like this:
At the archive ./config/middlewares.js