Remove Coupon

Hello-
When I add a coupon on the Cart page, and click “remove”, I get the notification “Coupon has been removed” at the top of the page, but it still says the coupon is there under “Cart Totals”. If I refresh the page, the coupon gets added again.
If I remove the coupon on the Cart page and go to the Checkout page, the coupons gets removed. Adding and removing coupons works normally on the Checkout page.

dev.beelinesupplies.com/
Username: hbthemes
Password:7h1z4HB7heM3z
Coupon Code: thank-you-me-ycba

How can I fix this?
Thank you!