Your Wi-Fi network configuration may prevent devices from communicating with Google streaming devices. In order to resolve this issue, you'll need to disable Access Point (AP) isolation, also known as "Client Isolation" or "Guest Mode," on your router. Refer to your router documentation to learn how to disable AP isolation.
If you don't have access to your router settings, or if you're attempting to connect through a guest, hotel or public network with AP or client isolation, you'll be unable to set up your streaming device.
If you're attempting to connect through a Wi-Fi extender, check your extender settings. You'll need to disable AP isolation on your Wi-Fi extender before setting up the streaming device to work with your Wi-Fi network.