Hmm, it also wouldn’t announce one post for me today. I think it may have to do something with quotes in the title in my case. A test post with one tag, content and without quotes in the title worked just now for me.
I had the same issue, suddenly non-registered users couldn’t comment.
I dunno if it was Discuz or WordPress update, but one setting was f’ed up.
you need to go to comment forms (/wp-admin/edit.php?post_type=wpdiscuz_form)
Edit whatever form you use (good chance is there’s only one), find section
“Display comment form for post types” 2 sections above the layout picker
and tick all three or whatever you need (they got unticked at some point for me, and were marked red). After saving the form, it should work fine.
