What does it mean if FB recruiter reaches out after 2 tries??

All my background is in data and if they ask me for designing instagram and how resolve performance issues in a service, obviously I will fail. I know I am solid in all the other TPM interview questions except this design. And I am only looking to stay in Data, reporting and analytics side. How should I respond to the recruiter who has access to my previous interviews feedback with facebook and still wants to talk to me. Looking for some guidance please on how to crack next time if I go in person.