Discounts on Invoices don't work

[ZachLTech]

Anytime I create an invoice and add a discount in the invoice editor then save & deliver the invoice, the invoice details don't show the discounted price. It also doesn't show the quantity or correct "Balance Due" in the PDF it produces... Am I doing something wrong or missing something? I'm using a self hosted instance.

Invoice Editor Example with discount:

Invoice Details for the same invoice which should display discount(s):

(Images sourced from another similar issue)

Image from generated PDF invoice section which shows incorrect balance due (It should be the same as the total):

[linear]

BIG-268 Discounts on Invoices don't work