I did try all three channels and did not see any change in behavior.
I have accessed it via duettest.local and it's ip address without seeing any difference. I have not done a wireshark trace.
After I posted yesterday, I was finally able to get a "stable" connection for a couple of hours - though I really have no idea why as I did not change anything. Turned it off for the night and came back this morning and I have the same issue. I bought the board from Filastruder so will contact them about the warranty and will reference this thread as you recommended. I was suspicious of the WiFi module but wanted to be certain I had not missed something.
Thanks for you input.