Active users in OIDC scenario between auth0 tenants

In our organziation we have multiple auth0 tenants. So far the active users are just the sum of all the active users of our tenants. What happens, if we use OIDC from auth0 tenant A to auth0 tenant B for the users to login? The user as a person has two different user accounts - one in A and one in B. These will also have different IDs, but the email might be the same. If such a user will now login into A, from there is redirected via OIDC to B, enters their password in B and then gets a token from A - will this count as two active users for this months (one for A and one for B) and thus double our bill or will it count as only one (presumably for A where they’llk get the token from)?