Very sorry for the poor experience, @DrakusW. I’m hoping with a bit of effort we can get a solid idea as to what happened, and what we at Brave may be able to do to improve your experience. Can you tell me a bit more about how you detected the missing profiles/files? Was this via the in-app profile-selection UI, or did you check the file-system itself, only to find all other profiles (with the exception of the Default profile) missing? Also, which version of Brave are you using (or, if you happen to know, with which version did you observe this behavior)?
There also appears to be Data disappeared, which might be related. I’ll be checking over that thread as well to see if these issues might be one in the same.