All transactions from Shopify are showing up as "Direct" traffic in Google Analytics. We first assumed this was an issue regarding our referral exclusion list, so we excluded the landing page that all shopify transactions are from (ourname.myshopify.com) and we also excluded checkout.shopify.com and checkout.rechargeapps.com. However, the attribution for all shopify transactions are still "Direct".
Note: The payment processor we use with Shopify is Recharge - and when users are going through the payment process on our website, they are not redirected to a different domain.
Is this issue related to cross domain traffic? Conversion issue in Google ads, Google tag manager, etc?