When using the “TS iFrame Embed” element, please ensure that the page you are attempting to show inside the iFrame is not protected by so-called “restrictive X-Frame Options“, which unfortunately, more and more popular websites opt to do. Websites protected with “restrictive X-Frame Options” prevent that site to be shown inside an iFrame that is located on a different domain. More information about that protection can be found here:
If you are attempting to use such a protected site, the iFrame will just show a white background without any content. That is NOT an error or bug with the plugin, as the protection has been put in place by the other website.