Are you sending ecommerce purchase value to GA4 in string format? This was the recommended way in the old Enhanced Ecommerce dataLayer documentation.

Since February 2023, GA4 has been experiencing issues in converting numbers sent in string format to number format. The issue applies to purchase events’ value, tax, and shipping parameters. If the conversion fails, the data will be missing from the GA4 purchase metrics.

You can investigate this in BigQuery. If the value of the “value” param is stored in the string_value field, it means that it hasn’t been successfully converted into a number. In that case, the purchase_revenue field will be null and the purchase-level revenue will be missing in GA4.

In GA4, you could see the missing revenue when comparing purchase revenue against item revenue. The fix? Send the value, tax, and shipping parameters in number format instead of as strings.