One of the most common reasons for data discrepancies in Facebook Ads is due to a mis-match in the conversion/attribution window settings being used for the query. If the setting for the query does not match the attribution window being shown in Facebook Ad Manager, the conversions and related values will not align.
[Changes are coming on Oct 12th, 2020 from Facebook that may impact your attribution window settings, please see Facebook Ads Changing Attribution Window Settings - Oct. 12th, 2020]
To verify if this is the reason for the discrepancy, check your current conversion window settings based on the product you are using:
- Supermetrics for Google Sheets: Select the Conversion Window in the drop-down in the Options section of the sidebar.
- Supermetrics for Data Studio: Select the Conversion Window in the drop-down in the connector setup page.
Then check the setting in Ad Manager - click on Columns: ->Customize Columns...
Look to the bottom right-hand corner of the columns page to see what the current attribution view settings are:
If the query setting does NOT match Ad Manager's setting, adjust the query so that it is using the exact same conversion window type. (You can also change the attribution view in Facebook if it is not set properly, if you have enough rights to the ad account).
WARNING - Different ad accounts may be using different attribution window settings in Facebook. If you are selecting multiple ad accounts for your query, make sure to check them all and adjust accordingly. You may need separate queries if you are not able to unify the settings in all ad accounts.