Conflict with WC Smart Coupons

Hi there!

I think I’ve found a conflict between TaxJar and WC Smart Coupons. When a user attempts to apply a Store Credit coupon, and totals are recalculated via AJAX on the checkout page, the coupon amount is reset to 0 and the non-discounted order total is shown.

Here is the setup:
WC 3.5.7
WCSC 4.0.1
TJ 2.0.1
Storefront theme (v 2.4.5)

To reproduce:
1. In the admin, go to WooCommerce > Coupons > Store Credit and send yourself a store credit coupon.
2. Go to the front end, add some products to your cart, and proceed to the Checkout page (this issue does not happen on the Cart page).
3. Apply the store credit coupon code. Notice that the discount displays briefly, and then when totals are recalculated, the discount becomes $0 and the order total is no longer discounted.

This is becoming a bit of an issue for our store, as customers who have bought a gift card (store credit) don’t see the coupon applying on checkout and bail from the process.

Please let me know if there is a better place to report this issue.

Thanks!
Will