Obsidian Publish redirects the root URL (/) to a named path like /home, which produces a non-standard URL and can cause SEO duplicate-content issues.
The solution is the permalink frontmatter property. Setting permalink: / on the homepage note serves it at the root path. However, the note must first be published with a different path before the permalink: / frontmatter is added. Publishing a note with permalink: / from the start doesn’t work. Publish the note normally, then update the frontmatter to include permalink: / and republish.