I noticed on setup of a new ip5 device (last night) that my SSID showed up as two seperate networks.
One was the normal SSID and the second one had a "5G" suffex. When I attemped to connect to the standard connection (without suffex) it would fail.
I logged into the SSID with the 5G suffex and it works fine ???
Scan the available networks and see if your router shows up with a suffex like 5G, if it does try to log into that choice...worth a try ?