Why some users have NULL preferences in database, how is it working? And also for some other users who has NOT NULL preferences after nulling it and make something as actor of this user, preferences are saved to database, but for users that always have nulled preferences this is not working.

    bradraj Why some users have NULL preferences in database

    Because they never saved their preferences.

    bradraj And also for some other users who has NOT NULL preferences after nulling it and make something as actor of this user, preferences are saved to database, but for users that always have nulled preferences this is not working.

    Can you provide steps to reproduce?

          luceos when user use default preferences then they are not saved in database ( set as NULL ), but only when user change one of preference then all preferences are saved in database?

              bradraj yes I'm right. When user using default preferences then it doesn't save in database ( set as NULL ), but if user have some changed preferences then they saves in database.