Jango doesn’t realize there’s a tracking device on his ship until he’s near the planet, and once he believes Obi Wan was asteroid chow, may have assumed that the Jedi had no time to report his position.

Or maybe the Slave 1 was just low on gas? 😉

As for the Falcon, Han didn’t even believe they were being tracked, and the DS plans needed to reach the Rebels as soon as possible anyway. (Tarkin could easily have decided to go after another planet friendly to the Rebellion.) It would have taken valuable time to go elsewhere, and scour the ship for the tracking device.