Definitely sounds like a router or IP config issue.
It’s not possible for the devices to have identical MAC addresses, but some network devices like wifi repeaters or extenders do some sketchy things like spoofing or modifying the MAC address. That could be contributing to the issue if you have something like that on your network.
@nate I didn’t have a repeater. I just added my travel router as a repeater and put the boards on it. The boards now get online in a few seconds. I’m going to run with this setup for a while.
I’ll throw in a wild idea to try, based on my experience with the Venstar thermostat wifi
It originally worked and connected without hessitation. After roughly 14 months of use, I started experiencing similar issues to what you described: wifi would connect and then disconnect, take forever to reconnect, etc
I changed my router wifi 2.4GHz band mode setting to “802.11n only”
(default setting is b/g/n mixed)
It IMMEDIATELY cleared up the issue. I’ve had zero connection issues since this change. I have no idea if something changed in the Venstar or the router (TP-Link) - but it’s been working flawlessly for 3+ years since I made the change.
I use this as a dedicated SSID for all IoT and home automation devices