Delete rest api of user is removing entry from x_user table of database and not from x_portal_user table so user get invisible from UI and api return success status.
Due to which if a user is updated to have username/email-id of deleted user, it will error message that this username/email-id already exists.
Also if a new user is created with user-name of deleted user, user get successfully created but his/her details are mapped with deleted user.
Rest apis used are:
Apis should remove entry from both tables x_user and x_portal_user.