About the visibility settings for notes in the posting form at the top of the timeline

Currently, in the settings, I have set “Default Post Visibility” to “Followers,” but

when I turn on “Show the post form at the top of the timeline” in Settings, the first note in the post form is set to “Followers,” but after I post that note, the visibility for every subsequent post automatically changes to “Public.”

(It reverts to “Followers” if I switch timelines or similar.)

This seems like a bug. Is there any way to prevent it from switching to “Public” and keep the “Default Post Audience” set to “Followers” even when posting multiple times in a row? Thank you for your help.