Using the Show Website Function
The “Show Website” message is made for showing your own website. The websites don’t generally have any problems, however some larger websites do block xframe which is needed. If they are blocked you will see this “x-frame-options”, “content-security-policy” in the header of that site.
https://abcnews.go.com/ is an example of a site that does not block this.
If a website is not working most likley it is because it is being blocked.