– “I’m very reluctant to clear my browsing history…”
To bypass your browsing history you could try a private window.
– “I forget what would usually appear in the third column…”
I don’t have a third column there; the right-hand third is simply the same grey background as behind the “Books” and “Recent Posts” elements.
Could the problem be the “Powered by [Wordpress]” icon? On my system this would appear below the specified area (uBlock Origin suppresses it), but it does at least contain the URL of the external site wordpress.org.