Camera Track Null Help!

I'm tracking a portion of my scene (I duplicated my footage and cut out just the part I want to track), but after I succesfully track the camera and create the 3d camera, the null I create is not behaving as expected. For some reason, it's taking the null properties of an track I did earlier in the scene. Why is this happening? I'm pick whipping a bunch of tracking markers like normal, but it just disregards that track and creates a null that sticks to the footage but 20 seconds prior. I'm very confused.