Duplicated users from a multiwiki deployment

Hi,
We are using a multi wiki setup in which we have the main wiki in which you can log in and then access the rest of the sub-wikis you have access to. Or you can also go to the subwiki and log in from there. Since I have uses both ways now I can see I have to different users created. Is this the intended behavior? Might I be doing something wrong?

Thanks.

Yes, if your subwikis allow local users. But you can configure your subwikis to allow only global users (User Scope).

I see. Thank you very much