Steps:

1. In storefront go to Orders list.
2. Go to order details.
3. Click reorder.
4. In checkout on Payment&summary step click Edit cart. -> User is redirected to the cart with products from order.
5. Click anywhere else on the system.

Result: Cart is empty. https://recordit.co/7mvbYwXpZ1 

Expected result: Cart should keep its state.