Hi @Louis,
yes that is correct. In addition I was using a cwicly custom template to fill in all the posts with one template.
With a good nights sleep and new energy I found the error.
Affter adding the repeater and the source, I was not able to add a div to the repeater. Hence I thought the repeater would not get any data. So now I added a specific post ID and it works. I set up my design and !! had to reset the specific post ID to current !! which is not as UX friendly but it is working. Well until I would have to edit that template again.