Does it appear if you turn on "show hidden files" or "show system files"? It seems that the data is there, but its not shown. Does the data folder display any storage size? Have you tried any other file mangers to see if they can detect the files?
I have the same problem, I have a Samsung S20 FE, I tried to create a new folder in my files data and I got the message in the photo, also tried with the app My computer and I got got the message access denied, I thought it's a virus so I installed an antivirus but after the check it appeared to be clean, I also factory reset the phone and still the same problem. Anyone knows what it can be done?
Dude relax and take a breather. This is an Android 11 change that everyone was aware of since the Google Android betas back in February last year. File managers don't have access to the directory anymore due to the Scoped Storage restrictions.