After fighting networking issues on a Windows 8.1 host with a vast variety of guest operating systems (Windows 7, Windows 8.1, Windows 10, Ubuntu, etc) I finally found that after setting up the bridged external connection all I had to do was disable and re-enable the “External” connection I created.
I cannot explain how many times I have deleted and re-created the bridge only to get a 169.254 address in the guests.
A simple disable and re-enable (with guest machines running) resulted in a valid IP address in each of the guests.
A very frustrating quirk of bridging a wireless adapter for use in a Hyper-V guest.