I am configuring my router Archer c6 v2 as my second router. 

I set a static ip to connect to my first router and everythings work great but I can not configure a google nest mini to the router.

The router has his own dhcp and asign ips to my phone (192.168.1.104) and my nest mini (192.168.1.124) on the same wifi 5G. However the app Google Home show me a error after the nest mini connect to the WI-FI: 

"Your Nest Mini has been set up successfully but we can't detect it. Check that your mobile device and your Nest Mini are connected to the same WI-FI network.
Disable access point isolation
If this feature is enabled on your WI-FI router, you will need to disable it. More information"

The Wireless setting are:

And I have activated the option UPnP. I have no idea what to try