Why Can not set any Actor into Actor to Track in CineCamera

Why Can not set any Actor into Actor to Track in CineCamera?
This is my process:

  1. Created a level sequencer.
  2. And then,created a new cine camera in sequencer.
  3. i added an actor and created movement animation for this Actor.
  4. then i ticked Enable Look at Tracking,and also setted a keyframe in sequencer.
  5. as the VideoTutorial, i want to set the Actor into “Actor to Track”,but nothing happened.

Is that any mistakes in my process?

That sounds like it should work. I tried this and it worked for me. Anything you’re doing differently?