I have a weird issue with a single contact.

The first post he is writing each day ("Moin") doesn't appear in my channel or any other timeline at all. Everything else he is posting afterwards does appear as expected. The contact is not limited in any way, the posts are set to get every single post from the contact. To interact with the post i have always go through his profile and find it manually.

I have other contacts that are writing almost identical posts in the morning (words, emojis etc.) and they all appear normally.

What else can it be?