In the past few days there appears to be one or a few dedicated spammers, initially posting hilarious "dental tourism" posts, then after a handful of those got quickly smacked down, he/they switched to posting innocent- and sincere-sounding replies to existing threads (most of which appeared to have the vapid, faintly fraundulent, cheerful-but-automated tone of AI-generated text). Then he started posting new threads, often with the same empty, AI-cheerful tone.
The agent behind these seems to have additional accounts they are using to respond to the other account's spam posts, making both accounts appear more legitimate. (I see at least two accounts actively posting that are definitely spam, AI or human-written - those have been reported - plus a couple more accounts that I suspect are accounts being "seasoned" to get past the filters and reporters but haven't quite passed the "oh, come on..." threshold yet).
I assume this is an escalation tactic to test to see what it takes to get past the forum's spam controls - and unfortunately, it seems to be working, at least somewhat, as actual human posters have been taking the bait and responding to their posts. The bots and their human drivers are adapting.
I've reported a bunch of them and I suspect all will be gone after the holiday weekend, but it's going to be a bit of a mess for web staff to mop up.
If you see someone with a very low post-count (say, below 30-50...this spammer has upped his post count to 27 currently), if you see a post has that whiff-of-AI, just maybe check out their post history before responding. As David in Cleveland noted, the AI is getting better and harder to detect (especially when mixed in with lots of other human-generated posts). This will probably get worse with the passage of time. Sigh.