I drove to 2 more towers that are listed as 4G on the NV Sites Complete map, and neither let me connect to 4g. So I have now been to the 3 nearest "4G" towers to my house and none allow me to connect with 4G.
But, I did get a 4g signal last night for the first time. Was at Taco Mac, the one in Johns Creek (Mathis airport road and peachtree parkway).
Signal was intermittent, I was able to complete one speed test, but the speeds were worse than 3G. I could hold 4G signal for about 5 minutes and then it would go back to 3g.
Then when I got home last night, I was once again roaming on and off and bouncing between towers.