Identifying Cohort Issues: New User Visibility in Your Analysis Plot

Problem identifying new users for building an active, new, dormant and resurrected users plot. I have created a cohort defined as users first seen in the last 30 days and that have performed and activation event in the last 30 days. Unfortunately, when plotting this cohort I only see New Users in the current and previous month. Not in earlier months. Probably I'm. Mistaking the semantics of "First seen". Any suggestion on how to fix this?