Well, good news - I'm able to reproduce the issue at will.
It's something related to the wifi / internet. Note, I don't have my car configured to connect to my phone or anything - but once you get past the magic dialog boxes about the connection, the car starts right up every time.
If you don't, well... You get stuck in the bad state, and you have to lock the car and unlock again. You'll notice a dialog indicating the wifi is disconnected, and it will start right up.
So it's 100% software related. The good news is that you just need patience to resolve; wait long enough for the infotainment to do it's thing. I'm more annoyed it seems to have some kind of "call home" functionality that prevent the key from being recognized.