When trying to access home page, Wordpress appends /wordpress to domain name which gives 404 error

When trying to access the home page, on https://www.andersonclassics.uk Wordpress appends /wordpress to the domain name as https://www.andersonclassics.uk/wordpress which gives a 404 error - there is no /wordpress folder, Wordpress is installed in the website root folder. https://www.andersonclassics.uk/about works correctly from the browser address bar.

I have four other WP sites which work correctly with similar setup

I checked .htaccess which has has only the standard WP settings.

Wordpress Address URL has https://www.andersonclassics.uk and Site Address URL has https://www.andersonclassics.uk. I checked the database table wp_options fields siteurl and home which both have https://www.andersonclassics.uk.

I've tried everything I can listed for 404 errors in the forums, and even tried changing the Theme to twentytwelve which works on my other four sites.

I'd appreciate your help.