UFO fleet seen outside of plane window for 20 minutes

Last night I was flying from NYC to FL, starting around 10:45 to until around 11:10 I could clearly see 4-5 UFO’s in the distance, maneuvering around each other and flying through the sky. They looked like a normal star constellation but would move and form into different patterns. Two of them would get consistently brighter once in a while, going from the brightness of a distant star to that of an approaching plane, and then dim out again. I watched them for about 20 minutes, dancing in the sky. I confirmed what I was seeing with the person sitting behind me, five “stars” clearly visibly moving in the sky while everything else remained stationary. For any skeptics, no they weren’t regular commercial planes, as I tracked a bunch of them flying through the sky and blinking at the same time I was watching this UFO dance. Sorry for no photo or video, this was at night and nothing was visible on my phone camera, especially at that distance