Triangle of lights that get bright and fade out and form other patterns

I went outside with my dog to let him out before bed, happened to look to the northwest and saw three bright white lights low on the horizon to the N/NW. They did not seem to be very close but I could see them well. At first I thought they were stars but I thought they seemed too low on the horizon to be that bright and shortly after noticing the three bright lights in an acute triangle shape, the top one faded out and the bottom two tilted at an angle to the right and faded out. After that I continued watching as the lights would get really bright and fade in and out. I saw a plane with red flashing lights which is normal for here but it seemed to go towards the formation and I could no longer see it once it got in the area of where I saw the lights. At one point one of the lights got really bright and another one looked like it came right up to touch the other and then faded away. The lights continued to fade in and out and I thought they seemed to be moving in a clockwise circular motion as they faded and got bright again probably every minute or two until eventually I could no longer see them after about ten minutes. I could not get any sky pictures with my iPhone but I looked at an app I have called Flightradar24 to see what planes might be in the area and there was nothing in the direction that I saw the lights in.