Cannot connect iPhone 6S to Apple Airport Extreme Time Machine Guest Network

I recently created Guest Network [Guest 'Name'] with Apple Airport Extreme Time Machine. The existing local area wireless network ['Name' Network] works OK - connections are fast and stable for 3 iMacs and iDevices.

However, the Guest Network will not connect, as reported by iPhone 6S. The iPhone 6S readily connects to the The ['Name' Network] and signal strength for both ['Name'] networks is 3 "bars" as as reported by iPhone 6S. I waited several minutes for the connection [a few feet from Airport Extreme Base Station], but it never happened.

Airport Utility returns the messages

"WI-FI Self-Assigned IP"
 
"Wi-Fi has the self-assigned IP address 169.254.87.8 and will not be able to connect to the Internet"

What am I missing to get the connection working? Different/None IP Address?

Will this work?

A 192.168.xxx.xxx address is usually not self assigned. Self assigned would be 169.254.xxx.xxx addresses, which appear if a computer could not complete DHCP. It could mean that the computer is not using DHCP, but is instead set up with a Static IP in this case.
 
Check to make sure DHCP is enabled by going to System Preferences > Network > select Wi-Fi / Airport > select Advanced. From here, select TCP/IP, and make sure "Configure IPv4" and "Configure IPV6" are set to "Use DHCP" and "Use Automatically" respectively. Then, go to the DNS tab. Clear out any servers you see here by selecting their IP Addresses and clicking the Minus sign.