It’s a new feature. I’ve actually found it very helpful

This is a new feature called reveal desktop. You can turn it off: Settings>Desktop&Dock>clear wallpaper to reveal desktop>stage manager

It’s not a glitch or sort of it’s just a feature of macOS sonoma ( which personally i disabled) when you click on the desktop hides all the tabs in order to let you grab files and move folders on the desktop without having to switch desktop

You can easily fix that in the setting(i’ll post here a screenshot soon as i can)

Forced system update? This isn’t Windows. What nonsense are you talking about?

System Settings, Desktop & Dock, scroll down to “Click wallpaper to reveal desktop” and set it to “Only in Stage Manager”.

This is some new behavior related to stage manager I think. May want to poke around those settings. I’ve noticed it too, but haven’t bothered trying to change it.