Maximum mileage for YEG-BNE is 12574 miles. So, the total of all segments to and from BNE can not exceed 12574 miles each way.
BNE-AKL-ICN-YVR-YEG is over 13,000 miles. You need to find another routing or change your stopovers.
YEG-SYD has different max mileage: 13212, which is why some routing will work with SYD, but not BNE.