Strange light with erratic movement, Cape May NJ

Strange light with erratic movement, Cape May NJ
This video was taken from the beach, looking east over the Atlantic Ocean what I originally assumed was a star or a plane, my girlfriend pointed out was moving erratically and changing in intensity. The object seemed extremely high in altitude, and I made sure to verify with ADSB exchange and Flightradar 24. There were no craft in that area though. 

In the beginning of this video it looks pretty unremarkable and dark, but soon starts moving in odd patterns and changing intensity quickly. 

Time: December 14th, 2024

Location: Cape May, NJ, USA.