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You're very welcome, we're all in this google together. I know that issue all too well, happens a lot with sitemap pages, sites that don't declare one type or url structure so they have site.com/ and site.com. I'm kinda surprised the CMS doesn't redirect the url when you create the friendly url, but glad they agreed to work on it, I would utilize your best offense and get the other customers of the CMS to upvote and squeak their wheels.  Since this also seems like a case of a CMS missing crucial features for site growth. If they don't fix this promptly, consider if possible a switch to a more commonly used CMS like Drupal, Wordpress or even Joomla, all are established for years with these kinda issues already worked out and in some cases extra addons to help assist. But understand, often the choice of CMS isn't always up to us. It does seem like for now, best you can do is try and reduce what you can on that page, but could be that the issue will keep presenting itself until the root cause is contained.