I received the same response from Shopify support as Muaravind did. Waiting for a Google response to see it they have any insight here.

I'm using the native Shopify GA4 integration.My totals in GA4 > Monetization > Overview match what I see in Shopify > Analytics. But it looks like the totals in GA4 > Monetization > Ecommerce Purchases aren't accounting for product discounts. So Anal...