TOPIC: Adding a second event to the cart when using a discount code on the first, zeros out the second

We have events, some of which have discounts that can be used, others do not. When adding an event that has a discount (and applying the code) to the cart, and then adding one of the events that does NOT have a discount, the second event's cost is zeroed out on checkout. This does not happen if the discount code for the first event is used OR if you add the non-discounted event to the cart first.

It appears tied to the precise order they are added to the cart - if you use the discount code (either one we have set up, both do this) for the first event, all subsequent events costs are zero. If you add those other events first and THEN apply the event with discount code, it works fine.