in the Gnus summary buffer I customized the threading appearance:

(setq-default
   gnus-sum-thread-tree-leaf-with-other "├── "
   gnus-sum-thread-tree-single-leaf "└── "
   gnus-sum-thread-tree-vertical "│ ")

When I'm reading my mail or mailing lists like emacs-devel via news.gmane.io it works as expected.

Expected behaviour looks something like this.

Unfortunately I can't get this to work in nnhackernews and nnreddit written by u/nnreddit-user.

There threads just get indented by whitespace.

Does anyone how what I am missing here?

Thanks in advance.