BQ20z45-R1 update status

We are using the BQ20Z45-R1 as the BMS for battery pack .2s5p is normal but 2s9p isnot normal .2 s9p 24 Ah capacity is to display on the charger when fully charged.2 s9p capacity is display 24 ah in discharger on the electricity. When we let it above the arrester discharge after 17 ah, And then into the charger is full of electricity,2 s9p 17 Ah capacity is to display on the charger when fully charged，Instead of 24Ah。Why?We are very confused。We need help.