Grouped view in a document library - Breadcrumb issue

I use the documents library with a double grouping. I include the library as a web part on one page (I'm not on a document library).

Now when I have the second grouping level open (as shown), I can't click directly on the first level (Varia) in the breadcrumb. The link does not work.

The desired behavior works fine when this is done directly in the documents library.

Does anyone know anything about the bug?