Gift card discount being added to Grand total

[Leonardo]

Firstly, apologies if this question has already been answered. I have checked online and it seems this may have been applied in a bugfix. I'm in the trial period of EasyCart Pro. Recently, as a test, I've setup up a new product as a Gift Card and, on redemption, the discount value is being added to the grand total instead of subtracting. I've checked all of the related PHP functions and they all seem to indicate a discount being negative. Any initial thoughts on how I may have messed this up?