https://www.dropbox.com/s/rgbvi0l4k5xb25u/Duet Stream.pcapng?dl=0

I was able to do a Wireshark capture (I hope I did it correctly.) I saved it to a file (1.7Mb). Should I upload it here or e-mail it to you?

Yes "Duet" was the name I put in the config.g file and "Duet.local" was the address I've been using.

I'm downloading Wireshark now.

Something odd just happened. I logged into my Duet from 2 different computers. On one, I connected directly to the IP address, and on the other, I connected to my "duet.local" address. The one connected directly to the IP address has stayed connected for over an hour now while the "duet.local" connection has disconnected 20+ times. I haven't tried printing yet. but this is the longest I've been able to stay connected.

Signal strength ranges from -40-50dBm, but -50dBM is the worst it gets. The board is sitting at the bottom of my Hypercube--I don't know if that is what's making the signal strength worse at 6ft.
Disconnections occur when idle. I haven't been able to print. I can't stay connected more than 10 seconds. I've tried channels 1,6, and 11. I'm using a Netgear Nighthawk and I had 4 other devices on the 2.4G working fine. I removed the other 4 devices in case they might interfere with the Duet.
AJAX retries are at 5.
And have no password at the moment (it was really tedious to have to enter a password 5 times in one minute because it kept disconnecting every 10 seconds.)

Both my computer and the printer are 6 feet away from the router. I have a raspberry pi 10 feet away that can has no problem staying connected.

I can't believe I spent almost $200 on this and still can't print 4 months later.

I just received my warranty replacement board and installed it. I'm getting fewer disconnect errors, but I'm still getting them. My M122 shows "WiFi signal strength -50dBm, reconnections 0, sleep mode modem."

I don't think I've configured anything incorrectly, but a second defective board would be quite unlucky. What are my options for getting this to work consistently?

Thank you.

@dc42 Yes, sir. All 3 and same result.

I've gone through the Troubleshooting AJAX errors and my last signal strength says 50dbm. I can't stay connected for more than a minute before I get a request timeout. I'm using firmware, server & web control 1.21. Where should I go from here?