partial payment is coming in as full payment with zapier

I’m trying to use zapier to connect gravity forms to invoice ninja. I’m almost there, but the partial payment is giving me lots of trouble. For instance, I have a deposit amount that is a product field so that I can charge that amount on form submission. But, when I try to make that a partial payment in the invoice, it doesn’t show a payment. It just shows that it’s due. So, I tried adding a payment for it, but it says that the whole balance has been paid. I’ve also had to add a deposit offset of the negative of the deposit to get the total to be right since the deposit is showing on the items on the invoice and throwing off the total. Any help would be appreciated. The form is here: in the bottom of the page on a button called Pleasanton Contract

Can you explain what you mean by “I have a deposit amount that is a product field”?

Are you aware the invoice itself has a partial/deposit field?