This issue is can be caused by either dirty rear tires or dirty track.
To properly clean the track, please follow the instruction below. Even if the track is new, please try cleaning the track if you are experiencing this issue. For the best experience, we recommend cleaning the track before and after playing with Anki Drive.
The tire cleaner can become less effective as it's used. To clean the tire cleaner please follow the instruction below.
After cleaning the tire cleaner, open the tire cleaner and roll the rear tires over the sticky part a few times.
Clean tire should appear even and uniform. Please see the picture below for reference.