We launched our new Shopify store recently and had so many problems with the Google/You Tube app that we decided to go down the GTM route. It took a while but we were finally able to track purchases (although some of them are missing, but that's a different subject). One thing we noticed is that if someone makes an order using a different currency than our default (GBP), GA4 records the amount in the non-GBP currency.
Both GA4 and Shopify are set with GBP as the default currency. Someone placed an order for 6 different products at Kč 133.53 each. The Czechia currency is showing on the Shopify order page but has then been converted to GBP.
However - in GA4 the revenue amount has come through as £13,365.68 for each product instead of £5.00 for each product which is the GBP price.
I'm not sure whether something in our Shopify Payments setup is incorrect, our datalayer code is pulling through the wrong value or a setting in GA4 is incorrect.
This is the datalayer code for the product price in the items array: