That’s what happens if the akismet key is invalid.
I was supplying Akismet to some clients until recently and failed to turn it off on (at least) one site and that’s what happened.. So they need to disable akisment and then get a working key or get the AI Spam plugin working.
Check the configuration of the AI spam scanner at /admin/plugins/discourse-ai/ai-spam — the admin can update the instructions there and ask it to be more forgiving. The default spam persona can be sensitive if there a lot of posts that appear unrelated or random in the topic…