Causes
Different data ranges
Different time zones
Currency
Wrong account
Data delays
Different dimensions selected
Including Different dimension changes the values
Differences between the API and the UI
Requesting help
Start with reports that match
Make sure the dimensions and metrics match. Select a single date, filter to a single campaign, etc.
Start adding dimensions and metrics until you see the discrepancy
Include screenshots of both the SyncWith report and the report for the data source's UI