A report file is a snapshot of your data at the moment it was generated. It doesn't update when your data changes. If the numbers in a file don't match what you see in Measure, generate a new file.
Go to Reports and open the report.
Choose + Generate new file, and download the new file when it's ready.
You don't need to log out and back in.
If you just changed data
After you add or edit data, Measure recalculates emissions in the background. A file generated straight away can miss changes that haven't finished. Wait a few minutes, then generate the file again.
Still doesn't match?
Check the same activity in Measure. If the activity page shows the right number but a freshly generated file doesn't, contact your Green Project team. Tell them which report, which activity, and the two numbers you're comparing.