The link below contains a step by step guide on how to setup your Streamyx or UniFi with your Netgear Orbi mesh network. This tutorial was written after I found out that no one in the Netgear forum (as of July 2017) was able to set up Netgear Orbi with Streamyx or UniFi in router mode.

Link: http://melvinchng.github.io/orbi/