2 unusual crafts, fully lit, flying erratic followed by sustained stillness

On June 1, 2019, at 22:30, son and I driving on Grove Avenue, and noticed 2 lit objects we assumed were drones, but based on erratic movement then sudden sustained stillness – we then revised our take as maybe military helicopter.  
We tried to pull over but cars behind us only allowed us to slow down.  They were clear, bright white light – perhaps oval or round, and seemed to be low-flying followed by a definite full stop.  By time we turned around – they were gone.  
I’ve seen thousands of aircraft and son has seen tons of recreational drones.  There was nothing familiar about this experience.