Any luck?
There is one or two more things to try? When I was setting up the test hidden DHCP server, for some reason now matter how many times I tried to switch it back to my main network it would not switch. After running WiFi.clearCredentials();, I was able to finally reconfigure the Photon to the network I wanted.
When I had you try to manually set the SSID, etc, all those attempts are in the WiFi memory and maybe we need to clear that out? Just an idea. Although these networks did not have a password, they are still saved.
REF: Somewhat related. Another code snippet to try if you tried to assign a static ip?
clearCredentials()
This will clear all saved credentials from the Wi-Fi module’s memory. This will return true on success and false if the Wi-Fi module has an error.