I have had my mesh network(4 points) up a running for a while now and it's been great.
I have put my router in to modem mode and my first Google router is connected to my router. Via my Google router I have then connected to a 24 port unmanaged network switch.
Everything is working perfectly.
We have installed a garden building to which I have ran a cat5 cable from my network switch. I have purchased another Google mesh router but can not get it to work.
Thanks for the reply EdwardT.
I have managed to get to the bottom of the issue.
Apparently you are unable to have 2 nest routers connected at the same location via The Home app.
I just added another location in the app and then added the garden building router to that location.
Voilà full speeds in the garden building now.