Calculation error under external pressure following EN-13345

Hello Everyone, 

I design a simple element of geometry under external pressure according to design code EN-13345. 

For me the value of nominal yield strenght (se) generated by Autopipe Vessel is not correct. 

According to EN-13445-3 §8.4.3, the nominal yield strenght should be calculated as follow : Rp0.2,T/1.25 with parameters : SA-240 316 : Rp0.2,151°C = 161 MPa ----> s= 161/1.25 = 128.8 MPa

The value generated by Autopipe is 99.08 MPa (in attachment).

Could someone help me to find the trick ?

Thank you in advance. 

Best regards. 

Damien MATHIEU