Hi @kaylaz,
The quickest way to find this information is to visit your overview dashboard, under Analytics > Dashboards, and look at your Conversion Summary, making sure that your conversion metric is whatever metric you use to track revenue (so not Active on Site/Viewed Product, ect). That will show you exactly how much revenue Klaviyo generated from Campaigns and flows.
If you want to get more granular, and break it down month over month, and separate campaign revenue and flow revenue, I’d recommend creating a flow performance report and a campaign performance report in your custom reports. You can then choose the time frame that you’d like to display the results for, and if you want to split that range up (for example, you might choose to see your campaign revenue over the past year, grouping by week).
It would be hard to explain the exact reason for this discrepancy you’re seeing without looking at your account specifically, but I’d follow the steps above to get a better picture about how much revenue you’re generating from Klaviyo and how much you were generating in the past.