Okay, call me crazy, but I’ve been through a bunch of the above and I found a solution that worked for me…
-Bought a v3 hub (first of anything like this in my house, yes, I’m a noob)
-Tried WiFi setup (along with factory resets) a number of times with no luck
-Tried it wired, and it worked fine for a couple week, but…
-I intended to run it using WiFi
-On Christmas vacation now, so more time on my hands
-Tried the factory reset and WiFi setup a couple times again, but still no luck
–I typically get through 50%+ of setup, usually up to 99%, but hang…
–Hub looks to reboot
–Comes back to blue blinking LED (which I understand mean that it didn’t get a DHCP address)
-I read through a bunch of posts, including the one above.
-Someone mentioned that the problem was the WiFi radio having issues and overheating…
So, I got to thinking… This might explain why at least one person had success after unplugging it for 3 minutes; Maybe it cooled down enough and their house was cool enough, or whatever, that the radio was cool enough to not overheat.
Here’s what I did (after at least 8-10 previously failed attempts), following the notion that “maybe it’s a heat problem.” I told my Samsung Galaxy S8 to forget my normal WiFi connection (in case it was automatically switching over to a stronger signal or something). I plugged in an extension cord and ran it over by my refrigerator. I then put my SmartHub v3 in my freezer for a minute or two to cool it down. Next, I did a factory reset and started the setup process again, leaving it in the freezer the entire time, except when I had to scan the QR code on the bottom, but then I put it right back in the freezer and close the door again. I then ran through the rest of the setup, selecting 5GHz WiFi (I heard the SmartThing Hub v3 prefers it, but not sure), it actually remembered my password from a previous attempt (surprise), and then it did its 50+MB update… It seemed slower than any previous attempt (and definitely slower than what my WiFi/internet is capable of), maybe due to not the greatest signal strength from inside my stainless steel friedge, but it actually worked. I took it out of the freezer after it said setup was complete, and I had a solid green LED.
Been online via WiFi for about 15 minutes now and the LED is still green and shows up in SmartHub.