group toots don't appear in main timeline

[htammen]

Hi,
I created the group @[email protected] a few weeks ago. In the meantime about 100 toots have been tooted.
But I don't see these in my main mastodon timeline. If I add the group to one of my lists, they appear in that list but not in my main timeline. Toots of other addresses I follow and that are also in that list also appear in my main timeline.
The following screenshot shows a toot I created as a response to the toot of another guy. In my response I mentioned the group. Hence it appears in the list SAP. But in my main timeline I only see my response to the toot, not the toot from the group.
Did I misunderstand something? Do I have to configure something? Is it a bug?