In case it helps, I started out the setup process on WiFi, and then plugged it into the router when it got hung up. I’m home now, and just tried unplugging ethernet and the ST hub remembered my SSID and PW and connected right up. So if you want to eventually run it on WiFi then you might want to try to at least progress through the point where you enter your WiFi info and it connects before you plug in the ethernet.
Also, here’s a thread where some ST staff chimed in on this. I just skimmed it a bit and it looks like this is resolved in a recent firmware update.