Cameras mounted to flash brackets of any brand tend to twist or rotate on the camera mounting screw. Cork or rubber friction pads help, but the real solution is to use a camera-specific Anti-Twist Plate. They act as an interface between the camera and bracket, pin-register to the bracket and conform to the camera's baseplate. This locks the camera to the bracket to prevent twisting. Because there are so many camera configurations, Anti-Twist Plates are sold separately.
NOTE: Camera Anti-Twist Plates are not compatible with QuickFlip models.