The thing is that the person you are now logged in as has not read those pinned topics. They are designed to stay pinned until an individual reads them, at which point they become unpinned for that specific individual.
So either these topics are important enough that everyone needs to read them and that’s why they’re pinned, or they’re not in which case you unpin them and they will no longer sit above latest.
If they read the post it will become unpinned for them automatically.
If you log in and read the pinned posts, what do you then see on the home screen?
Also take a look at Force Mobile Homepage in case that is helpful.