This could be a new feature rather than a bug (and this becomes "feedback"), but a given series page no longer shows available prepubs to those who aren't logged in (or don't have a membership); it used to show that information to everyone (a change within the past couple of months).
In one sense, I understand that those without a membership don't "need" to see it as they don't have access to it; but in another sense, it seems like you'd want to show people what they could get. Plus the site logs me out often enough that I personally might prefer that even with membership.