Possible Bug in frontend part of RelatedItemsWidget

Hi

I have a mosaic-tile with schema.Choice-field. This field uses the CatalogSource and a slightly adjusted RelatedItemsWidget (language-dependent favorites). Additionally I use the "selectableType" attribute to restrict the types.

Problem:
In the top-folder/navigation-root the first 10 results are link-objects. They aren't displayed since they are not in selectableType and also not folderish. As a result the widget says "No matches found" altough there are folderish-results in
the third batch.

I guess it's a bug in the frontend-part because the batched results delivered by the backend seem ok. But there is no following request after the first one. This is different to a normal page (not the top-folder/navigation root)
because there are following requests for the same situation. Maybe the "One level up"-element has something to do with it working on normal pages.