If they only have mmWave 5G in their area then that's sounds about right. mmWave 5G only has an effective range about 500-1000 feet from the tower and heard it doesn't go through walls very well as objects blocking line-of-sight between tower and phone.
I noticed they are installing mini towers outside my neighborhood and told these are AT&T mmWave antennas. There were two of these about 1000 feet apart and guessing there will be more.
I can see it in the city where you can put one of these one every city block intersection to make a grid. But a grid of mini towers in the suburbs?? Instead of Parkland, they'll have to rename my city Tower-land.