We don't have WP Rocket installed on the forum subfolder. It is installed on another site/subfolder, but deactivating it had no effect. Also disabled ...

Thank you both for your answers!

Set the option as described. We tried another post and it seemed to work fine, so I believe we're good now. Thank you so much!

Thanks. It was in fact one of the plugins that caused it. Fixed that, but then to the next problem. Post shows all formatting at the beginning of a pa...