"social_auth_usersocialauth.user_id" didn't match "auth_user.id"

[wowkin2]

In my django application I have 2 tables: auth_user and social_auth_usersocialauth.
And the problem is in that the same user has different ids in these tables (auth_user.id and social_auth_usersocialauth.user_id).
So I got a problem when I wanted to figure out who is 2000th user on my site, each collection has it's own object with id = 2000.

Which of them is more reliable? The only option to register user was social auth backend.