Milestone Billing with Down Payment Clearing

Hi all,

I would like to customize our existing payment order for a machine shop. I want create in the billing plan a machine for example:

Date description .......... BR ..... Billing Type

-30% Down payment....4......(FAZ)

-30% Partial invoice ......1......(FAZ)

-20% Partial invoice......1......(FAZ)

-20% Final account .......3 ...... (F2)

So far so good, but when combined with down payment and partial invoice I get the wrong amount on the final invoice. The down payment does not recognize the final invoice.

Additionally when applying the down payment request, I get the error message, that I this partial invoice (billing rule: 1 or 2) can create only with the billing rule 4 or 5.

What must be set here, what suggestions do you have?

Thanks in advance

Best Regards

P.S.: I attached 3 Pictures for this Problem.