Hello there, The mini cart which shows up from the right side when you add an item to the cart doesn't respond as right after the action. It seems those items that you just added are in the cart but the mini cart doesn't show it has those items, because if you go to other pages and try to bring the mini cart again, then those items are there. Here's my Shopify address https://episquad.myshopify.com/ using Narrative themes. Just in case, the password for the shop is 1. Thank you so much.
It seems that the JS needed to put the item into the mini cart did not run. Do you know if this worked when you first acquired the theme in its default state? If so, perhaps the theme was modified and the script was accidentally removed. See if you can get a fresh copy of the theme and check that. You may be able to copy what's missing into your modified theme.
If not, you might want to contact the theme author about that. They may be more inclined to bugfixing their themes and providing a more native solution.