I was having troubles as well...
But them found this useful video: https://youtu.be/oR47DReyas8?t=273 - a bit old (from 2015) - but works flawlessly!
The part explaning the integration between YITH Infinite Scrollingand the WooCommerce starts from 4:33.
It doesn't matter whether it is Divi theme or another WordPress them...
Here are my settings (also shown on the screenshot below):
Navigation Selector: .woocommerce-pagination
Next Selector: .woocommerce-pagination a.next
Item Selector: li.product
Content Selector: ul.products