This will happen if you have a return/credit on the invoice, a negative line item that is not a "Discount" type item. When data is recorded in this way, it creates internal "links" on the invoice, and the credit treated as if it pays off other parts of the invoice.
Based on your example, the credit on the invoice amounts to about 42% of the invoice total before the negative line item(s).
For example, if you create an invoice for a product, and then add a line for a return of another product (presumably that the customer purchased on a prior sale), that return is considered 'final' - the end of the line for that transaction, and so it acts as a payment against the invoice total.
The same thing would happen if that return was entered as a credit memo and then the credit memo applied to the invoice.
This is true except for Discount type items, which are treated differently and considered part of the sale, and not as a return / not as something to apply to the sale before actual payment is received.