By default, items added to the cart are sorted according to the settings in
Wppizza-> Layout : Items Sorting and Category Display
If you wish items to be sorted and displayed in the order they were added to the cart by the customer, make sure that you do NOT enable
Wppizza -> Layout -> Group, sort and display menu items by category

and add the following to your wp-config.php


somewhere before
/* That's all, stop editing! Happy blogging. */