cart has different number of items on different pages

Hi. I’m not sure why this is happening. When I add an item (or 2) to my cart, the cart in nav has a different item number/total depending on which page I am on. It seems that when I click the logo to return to the home page the cart is wrong, but on the other pages the cart is right.

I am testing on safari and chrome on a mac os 13. All WP items and plugins are all up to date.

The site is http://sscy.org

The page I need help with: [log in to see the link]