xenforo metadata should be enough as it does work fine for this community and a few others i checked... in the end google usually decides themselves what they want to use. here is the relevant documentation. they do the same for title tags. google search does not always show the title you actually have on your content.
When Google lists a page in search results, it shows the name of the site the page comes from: this is called a site name. Learn how you can provide a site name to Google Search with WebSite structured data.