Unable to change my Forum's SEO settings

Hi, I’ve recently designed a website and have connected a premium domain for it.

I am going through the SEO settings for each page, changing them to match Walks Through History. I have been able to do this with all of them apart from the Forum. My SEO settings for that page are:

However, when I publish the website, that page still shows:

So I have no idea why the forum page won’t change like the other ones. I am assuming this is preventing me from completing the SEO checklist:

As I can’t think what else it could be. Any please would be greatly appreciated.