Pop up code appearing after close of footer

I’m seeing popup code in the source code after the close of the footer tag. This is troubling as it is presenting crawlable content where no content should ever be found. It is also not contextual to the pages and is appearing globally.

I’ve discovered this on two different client sites that use different themes. Only one has caching but disabling that made no difference and the site without any caching or minification has the same problem.

I have already followed the instructions found at https://docs.wppopupmaker.com/article/304-why-is-my-popup-showing-in-the-footer-of-my-site

This is a major SEO issue as it presents content where it doesn’t belong and dilutes the semantic value of headings.