This is due to the original installation or manufacture of the blinds. The easiest way to fix this is as follows: Unroll the blind fully until the bare tube is visible. Stick a piece of masking tape (as shown below) to the end which the fabric is tracking away from. Test to see if the issue is resolved. Note that this is a trial and error process and you might need to add more layers, or to adjust the length of the tape. Some small amount of tracking is normal as long as it doesn't cause the side edge of the fabric to rub against another component.