Fetching relation but missing populated fields

Hey guys im tryting to get fields that you only get with ?populate=* in a deeper level

Background: I have a forum with topics. Each topic can have Contributions, so i created a n:m relation

Now im trying to display all Contributions for each topic so my fetch looks like this:

    fetch(`http://localhost:1337/api/topics/${this.themeId}?populate=*`, { headers })
      .then(response => response.json())
      .then(topic => {
        console.log(topic.data.attributes)
        const topicContributions = topic.data.attributes.topic_contributions;
      })
      .catch(error => console.error("Error:", error));

when console logging “topicContributions” i get an array for topic:contributions like this

Problem: I dont get the populated content from topicContributions. For example people can upload a featured Image for their Contribution. That field is missing but crucial for my lists of contributions.

Any idea?

With this i managed to get the Image fields as well

?populate[topic_contributions][populate]=*

but now my problem is that the all fildes in level 1 (topic) are not populated. Only the topic_contributions field can be seen