Wrong Due Amount

I was very excited about your plugin and I wanted to test it. But unfortunately it has a bug and doesn’t work for me. I was really sad, because it supposed to have awesome options I was looking for.

Here is details if you’re wondering:

First deposit payment works fine (3$Deposit +23,83$ shipping costs=26,83$): https://ibb.co/HrvDQj1

But when customer goes by link from email or from my account page to pay Due amount, then things go wrong. As you can see from the example, Due amount is 7$. This is what customer sees when trying to pay Due amount: https://ibb.co/Qv4k450 Customer is required to pay 26,83$ again

But this is not all! Let’s pay 26,83$ second time and see.

After incorrect second payment (customer already paid 53,66$), registered customers can reach my account and see their order is still partially paid : https://ibb.co/RgxhJHc By clicking the button we finally got 7$: https://ibb.co/XjRB8PY Let’s pay it. Our order is finally paid: https://ibb.co/Zmdgx8z So, as a result, customer paid deposit+shipping twice + due amount.

Guest customers can do nothing. That turns that they just pay deposit+shipping twice and never pay due amount

The page I need help with: [log in to see the link]