Shopping Cart does not Display all the Items that were Added to the Cart

This is a solution that Customers can apply when the Shopping Cart does not display all the items that were added to the cart. 

Perform these steps in order to prevent this issue from being encountered by the shoppers

1. Navigate to Setup>Site Builder>Set Up Web Site>Appearance tab>Shopping Cart section 
2. Look for the Display Order of Cart Items field and select Most Recently Added Last.
3. Save the changes