This web page may help explain the Windows 11 version of file history.
I have a 1TB boot drive and a 10TB data drive for photo/video editing.  In Windows 10, I used File History to make incremental backups of my data drive to my external 12TB USB drive as a backup.  This has saved me a few times.  However, File History in Windows 11 removed the ability to add folders apart from the default folders.  This really is bad and now need to figure out an alternative backup strategy.
Windows 11 File History removed add folder ability