Need help and techniques to debug DNS failure on Facebook and Instagram using Pihole with Unbound

Thank you. unbound-checkconf says its happy. Pihole was / is working ok except for these two domains. I can query instagram.com but not www.instagram.com for example. www.instagram.com is an aliases for something within facebook.com and that seems to be what is hit and miss.

My Pihole was working except I could not get archive.is. This page suggested installing unbound which solved that problem.