After update Brave to [Versión 1.7.98 Chromium: 81.0.4044.113 (Official Build) (64-bits)] and check that the folder has permissions, still the same, Brave don’t store passwords.
— .config/BraveSoftware » drwx------ 32 user user 4096 abr 29 12:51 Brave-Browser
As well all subfolders with profiles.
thanks