Difference between STAAD Pro. and Manual Calculation for Concrete column design

I design a very simple column to verify the concrete column design using ACI-08.

Column Size : 250 mm x 250 mm

Bar arrangement : 4-D20, (D12 @ 250 mm for tie)

However, P-bal and M-bal in Analysis output are not same with manual calculation.

Please help me to verify below design result.