Wrong Tax calculation on PO in SRM

Hello,

I have a PO with 10 items. Tax calculation is wrong for 9 of them and it is true only for one.

For example, in the image below, TAX amout should be 7.83 (48.96 x 16%) but it is 15.66.

Could you please help me solving this issue? Is it a configuration matter? If yes, where should i check?

Thanks a lot,

Hazem DAOUD.