Why I cannot see folders in Finder ?

I have a new MBP M2 (macOS 12.6.1) and for some reason, most folders in sidebar of finder have disappeared.

Even though in Finder Prefs all these are checked, they do not appear in sidebar:

Desktop

Documents

Downloads

Pictures

and others

Locations checked include: external disks, cloud storage, etc...

I can only see in sidebar:

Icloud Drive

Shared

LOCATIONS:

Macintosh HD

Network.

I want to see in my sidebar:

Documents

Dropbox (I can locate it, but find no way to see it neither in Finder Prefs nor in Sidebar)

Downloads,

others...