Omg finally got this plug to work. If not for Covid I probably would have returned long ago. Downloaded new Smart Tings app, set phone to 2.4 Wi-Fi, turned off cellular data, updated iOS 13.4.1 and now I don’t have to social distance at Best Buy. BTW I did have to run install three times as failed at 99% twice.
I had the same problem in Android as well. But turning off the cellular data and trying again that way did the trick. Also, if you have a hub, I don’t think it matters after setup if you use 2.4 or 5.1 Wi-Fi.