The not working one is:
[jeherve_post_embed url=https://gastrobrains.de wpapi=true include_title=false include_excerpt=false include_content=true tag=conduct]
This works well for me right now.
I’ve opened it in an other browser (chrome now, firefox before). I’ve cleared browser caches. I do not have any cache plugins in both wordpress sites. Browsing to https://onlinespeisekarte.com/code-of-conduct/ still shows me all posts of that category.
The category is just for organisational reasons. As i understand it doesn’t matter if i keep the posts in or not.