The satellite antennas used to uplink a video feed like this have a very small beamwidth (around 1° depending on antenna size and the frequency they're using), so you need to keep them pointed precisely at a specific point in the sky. They rely on a sensitive IMU (accelerometers) and fast motors to actively track the satellite while the platform moves. They're quite impressive to watch in action[1], but I'm guessing they're no match for the shock and vibe of the rocket landing.

1: https://www.youtube.com/watch?v=k79vfwUkeYk