3d camera tracker sometime doesn't show the red disc after tracking

Thank you for the explaintion. Today I tried to run the camera tracker with the same shot, and it worked just fine. 

The first shot, the one with no target, is not at all suitable for camera tracking. Camera tracking requires a significant amount of geometry in the shot that is not moving. All of the tracker marks are on the moving vehicle. There is no camera solution for that shot. You might be able to move forward a few frames and get a target to show up but it may only give you a tripod pan solution. Camera tracking only works on shots suited to the tool. There are ways you can work around some problems, but if that shot is a pan following the vehicle down the street or a tracking shot following along with the subject, the camera tracker is probably the wrong tool. It would really help if you told us what you were trying to do with that shot.

I fail to see your point. Clearly your first clip is full of motion with no static elements to even produce a spatially consistent ground plane, text layer, solid or whatever. You seem to have a wrong understanding how this stuff works and what it can do. AE's 3D camera tracker does not support inverse motion tracking. It can only handle static scenes where only the camera itself moves. Therefore the behavior is correct within what you can expect. If you need more advanced options, you have to invest in commercial third-party tracking apps or use other compositing tools like Nuke.

Mylenium