Hi,

Unfortunately I don’t have another solution as per what is posted in that thread / this one https://wordpress.org/support/topic/not-working-with-divi/?replies=4

If that doesn’t work for your site it could be there’s something else also active that influences the number or posts/products per page that may override this again.

Something you can try is override the PPP again with this code snippet
add_filter( 'loop_shop_per_page', array( Woocommerce_Products_Per_Page()->front_end, 'loop_shop_per_page' ), 100000, 1 );
(note that this is a quick and dirty snippet, it can be used for testing if it works, but should be improved upon live usage)

Cheers,
Jeroen