3D Tracked Points Drift After Camera is Created

John, 

Reading the manual and following a solid training regimen is critical to learning how to use AE. The Home screen in AE has links to some really good training material.

This problem, the problem of tracking points not following the expected path is only solved by setting the proper analysis settings in the Camera Tracker and picking the right points. In a shot like this, setting an origin and ground plane and then adding a reference solid and a camera are critical to figuring out how the tracking is going. If you just add a null like the OP said they did, there is no reasonable way to verify that the points that were selected are on the same plane. Most of the time, inexperienced users don't properly set up the tracker or pick the right points. 

As far as always saying the same things, that only makes sense. Let me give you an example. I am working on 3 different compositing shots right now where I replace a TV screen on a TV in the shot. The shots all have moving cameras. The shots are from three different angles. The focus shifts as the camera follow the actor. One of the shots requires some rotoscoping. All of the shots involve adding lighting effects from the TV Screen, focus changes, motion tracking of one kind of another. Here's the problem. Every one of these three shots requires a different technique, different tracking techniques, different masking techniques. Do you see where I'm going?

Almost every problem you face in After Effects has dozens if not hundreds of possible solutions. Almost every problem that you see with previews, crashes, or any other technical problem also has dozens if not more possible causes and solutions. If we don't have details, most of the time, most of the replies on the forums are just a waste of time. If someone, like the OP on this thread, at least posts screenshots and tries to describe their workflow, we have a chance to help. The more info we have, the more likely it is that we can help solve their problems. Let's take a look at the original post.

The first screenshot shows a 3D cursor and the OP says no camera or null is created. This tells me that it is highly likely that the footage layer is 3D. That is an error that would be solved by reading the manual. There could be another 3D layer in the comp but because the screenshot is cropped and no workflow description is offered we don't know. As you look down the stack of screenshots the 3D cursor does not move from the center of the frame so this tells me that the OP has either added a camera to the scene not using the 3D tracker or that the footage layer that was tracked is a 3D layer. Again, reading the manual, or providing details would point this out. 

The assumption that tracking markers move over time is also incorrect. Reading the manual explains that. The markers do not move, then attach themselves to details and appear and disappear as time passes. This is also normal.

Both Mylenium and I offered a place to start and that is all we could do without more information. 

Since you are new, if you have problems and you want answers, give us workflow and system details and screenshots of the entire UI with the modified properties of the layers giving you problems revealed. Then we can help. Just putting up a few cropped screenshots and telling us what you think you see does not help us help you at all.  That's just how it works. 

Both Mylenium and I have been using AE for a very long time and helping folks on the forums without compensation for a very long time. Don't be offended if we ask you for more info or tell you to go do some homework. That's how you learn. Just for reference, here's one of my favorite graphics: The J3 and the Shuttle both fly with a stick, both have to be landed by hand, and you need training to safely operate both aircraft, but if something is not going the way you want it to go, it's a lot harder to find the problems in AE than it is in Premiere Pro. You need to do your homework.