Both dns here are running on top of IoT devices (BeagleBone & Raspberry Pi) the DHCP from the Internet provider's box override its dns for my internal ones.

https://www.reddit.com/r/pihole/comments/9w5swx/i_think_ive_managed_to_block_youtube_ads_with/

TL;DR;

nslookup manifest.googlevideo.com

On the DNS (using dnsmasq here via pi-hole)

vi /etc/hosts

 <IP from nslookup> manifest.googlevideo.com

reboot/relaunch dnsmasq