I know this is an old thread but if someone still needs to know how to do this, This how I figure it out.
1. Copy the last ‘Attach Point’ keyframe in the timeline. (only ‘attach point’ key)
2. Move the Track Point to a new location in the viewer. (New proper tracking position so you can continue tracking.)
3. Now delete that last ‘Attach Point’ keyframe (previously copied). Don’t delete the ‘Confidence’ and ‘Feature Center’ keys. ( You’ll see in the viewer attach point moved to previous tracked position.)
4. Click on ‘Attach Point’ name in the timeline to select it. and then paste that key we copied.
5. Now you can continue the tracking.
Hope the help someone.