Global Default Feed Sort By Not Working / Reverse Order Issue

I’m experiencing some issues with the Global Default Feed Sort By feature:

Issues observed:

When I select any option other than Latest in the customizer, the selection is saved, but the feed still shows posts sorted by Latest. If I disable the Feed Sort By Options, the selected default sort works as expected.

My specific Issue:

I want to set Default Feed Sort By: Following and disable the Feed Sort By Options.
When I do this, the feed correctly shows the curated "Following" content. However, the posts appear in reverse chronological order: the oldest post shows first instead of the newest.

How can I reverse the order so that the newest posts appear first in the “Following” feed?