Atlas Towers - Where's the radius ring? Why do they burn?

Every so often the towers in my atlas will show their radius but 99% of the time there's nothing with or without a tablet. How do I get this to show up? It seems completely random.

Also, why do some of the towers light up and burn? It only does this when the ring is showing so how do you get them to burn? Is it doing something special? Are these things supposed to be constant and it's bugged?