I just got this today. The app seems to be terrible unless my system is just broken. I'm coming from Asus mesh (ax11000 router with two satellite ls). 

This app gets all the way to "testing Internet connection" then says there's no Internet. Yet, I can connect to the network on the device. 

Another issue, there's no "main" unit. There's no clearly defined LAN port. It looks like three nodes in a box without a router. 

The setup manual is useless, it says download the app. I have to be missing something. This is a terrible first TP link experience.