Site always reverting from "all" to "local" when refreshed?

https://lemmy.world/post/81114

Site always reverting from "all" to "local" when refreshed? - Lemmy.world

I changed the setting to default to “all”, but it keeps reloading to local, is this a bug? (desktop browser)

I'm really new here and don't quite understand the difference between local and all, could someone possbily explain?
Local shows communities on your instance. All shows communities from all instances
I am also new, but I think local shows only localy created communites and global shows all communits with communites from other instances (if they are traced)