why fluid pressure at the bottom in water tank is different...? Please help

I am checking tank design (pic 1) and expecting to get at least 200 mPa pressure at the bottom. ( hand calculation) . In pic. 1 the model is show about 20 mPa and other part of bottom over stressed. In pic. 2 I have only simply bottom part (pic 2) and results looks like close to hand calculation.

Could somebody help me why in full model result is different? Thanks in advance!

pic 1

pic 2