OOoohhh I think I found it!!!
Inspired by your post, I paid attention to the inconspicuous ‘mark all as read’ button, which also eliminates those bodies.
Thanks for your help!
You are right, Robin!
I think this must be bbPress Unread Posts v2 V 1.08, of which there is no newer version according to the plugin settings
I can do that with plaesure. It is this little yellow indicator that tells me (if I’m logged in) that there are new posts in this forum.