Looker Studio - blended data inconsistencies

Hi,

I’ve been working on a report which takes data from Google Ads and a Google Sheets. There was large data inflation with the blended data and I couldn’t figure out why, everything seemed right. For example, the Google Ads data source might have a metric with 1 million, and the blended data could have like 50 million.

Then I isolated the blended data to only include the Google Ads data source. I created a simple table using this blended data (which at this point, only included Google Ads), as well as a second one which used the Google Ads data source. And still, the data was wrong. Although the data discrepancy was much lower, the blended data was now lower than the Google Ads data source. For example, 190.000 vs 300.000 respectively.

Could anyone please provide any insight?