Not sure if this is related but I just received a notification for a new reply and it turned out to be a quite old comment from 5 months ago:
I block all mags from all Cloudflare instances. So sometime after posting to [email protected] I blocked it. I still get notifications (which is good), then I unblock it just to read the response then re-block. That’s not likely related, but something happened in the past couple days that apparently caused a “seen” flag to get unset. It’s not in itself worth chasing up but maybe it’s a clue as to whatever happened.