This is basically the process I myself and many others have tried multiple times ad nauseam. I followed this exactly, adding in the phone power cycles (only difference to previous procedure.) The problem I have is that at step 8a, the grill connects to my WiFi, and I get the "Nickname your grill" prompt. After entering a name, the app goes right back to main screen, with no grill attached. And the grill remains connected to my WiFi, but doesn't download the v2.0.0 firmware.
To get that to happen, I must "Forget Network" on the grill, and start pairing setup once again. This time is does download v2.0.0, but then errors out with the "Grill failed to download certificate files" message. From this point on, it's a constant loop. Pair setup -> Certificate error.