You have reel defect when the tube is closed in the middle but open at its end. This defect can be caused by the roll bi-conicity.

CAUSE 1: The plate you are using is too thin in relation to the machine performance

SOLUTION 1: There is no other solution than bending the material with a lower Capacity machine

CAUSE 2: The plate pinching pressure is to weak

SALUTION 2: Slightly lift the bottom roller to increase the pinch force.