magento2 – Products in category not shown even though counter shows right amount?

Magento 2.4.2

For some categories the product counter shows the right amount, but the list of products is empty. I debugged a little and the product collection is empty. This is what I did so far:

  • full reindex
  • checked visibility
  • checked inventory
  • checked product in website and category

Everything seems to be fine, but still, no products. Any idea what to do?