TAX in the invoice not calculated relative to the amount of the invoice.

Hello experts,

After using the billing calendar already set up, the amount of VAT generated in the 1st invoice corresponds to the total amount of VTA of the document whereas it must be calculated relative to the amount of the invoice.

For exemple :

Net value of sales order is = 100 000

the MWST (of sales order) = 20% = 20 000

the net value of 1st invoice is 30 000 so the VTA showing is the 20 000. it should be 6000 (20% of the 30 000)

Sales order :

27.png

27-1.png

Invoice :

27-2.png

Please help me