When doing a site audit with semrush, I use to get no errors; however, now I get a lot and they all seem to revolve around your forum pages. I have included some screenshots. You say that you are handling seo on the backend with your plugin, but how can I get rid of these errors? I have included screenshots of what I am seeing. And yes, this was run right after performing all your maintenance actions. I ran every one of your mainenace actions, and then I ran the test.
Thank you for the detailed information.
Search engine crawlers (like Googlebot) do not store or accept cookies when they visit a website. Because your page relies on cookies to serve dynamic "unread posts" content, a search engine bot will always see the exact same "logged-out" or "default" state across those different URLs, triggering the duplication alert.
While the Semrush alert itself is a false positive caused by the bot's lack of cookies, the underlying structure poses real SEO risks if not handled correctly.