macOS Big Sur Users folder issue I have just updated my macOS to macOS Big Sur but I am very confused about the organization of users. On my previous macOS version, I had an account with all my applications and files stored on Macintosh HD - data disc, however, after updating to Big Sur, a new user had to be created and stored on Macintosh HD with my old user being stored in Macintosh HD - data. The real problem is, that all new downloads, applications, any new files and also desktop are stored in the newly created user on Macintosh HD. How come, since all user data should be stored in the Macintosh HD - data disc? Do I have to migrate all those gigabytes to Macintosh HD? My Mac is now the same as a factory new one, however, my old user is stored only as a folder in Macintosh HD - data. I will appreciate any help, I need my Mac up and running as soon as possible. Thank you.
First thing - don't try to fix anything.
Check when your last back up was done. If you don't have a backup - stop and back up this Mac to a blank external drive (ideally) using time machine and be sure you have a good backup before proceeding.
Now write down some details:

When did you start the update.
What was the previous version ( softwareupdate --history should tell you all the recent updates on the Mac)
What is the state of your storage ( diskutil list is a good indicator to share with someone technical )

Decide if you want to use Apple, someone local to work with, or trust us randos on the internet to know what your setup is and hopefully give good advice. The problem with us, is no matter how smart, honest and well intentioned we are - we only see your word and if you are mistaken, we may give you bad advice. Also, we could just be evil but hopefully if you are patient - votes will help see if we're all evil together or someone has good advice.