Not sure on this one, but some ip's refer to the crawler of bytedance.
So best to add crawl .bytedance .com to the denu list in robots text.
If they adhere to the robots txt rules, this would likely already give some results.
However, if ip spoofing is in practice (ala vpn or alike) it is undo-able without complete block chains.
However, you also could use search engines/bots disallow the forum only..
above is basic example use (bin/private/tmp in this case are disallowed). NOTE !! the * means ALL for a specific one, change it to name.
Hope this helps
(ps edited content of first post> markup spoil)