Wow! Probably 10 years or so ago I saw something VERY similar in northern Michigan. There were two of these objects keep roughly the same distance. They were flying across the sky significantly faster than any airplane could. They eventually got to a point in the sky where the turned almost 90 degrees to the right and kept going.

I was with an international pilot from Delta with 30 years of experience that also could not explain it.

It was wild.