By default, the side brushes of the robot do not rotate. This is by design.

1. If you want the side brushes to rotate in specific areas, open the Anker eufy app and go to Settings > Area Selection, then select the areas where you want the side brushes to rotate.
2. If only one of the side brushes rotates, this may indicate a hardware issue with the robot.

Here is the reference video：https://d3pkbgk01oouhl.cloudfront.net/upload_file/prod/Q3-1.mov

If you have any other questions about the S2 Pro, please don't hesitate to contact eufy Support Center for further assistance.