Google has fixed a bug where Google Ads were overreporting conversions between November 11 at 12:01 AM PST through November 20 at 11:59 PM PST. This specifically impacted advertisers using non-last click attribution models and impacted reports in all Google Ads interfaces, including any report data downloaded via the AdWords API, Google Ads API and Google Ads scripts.
Google said on Sunday, November 24th that it fixed the issue. Google wrote the issue is now resolved "for advertisers using non-last click attribution models has been fixed and the data is now correct except in the Search Query Performance, Geo Performance, Keywordless Query, and Keywordless Category reports."
If you downloaded any of the fields in the table below or any derivative custom columns using the AdWords API, Google Ads API and Google Ads scripts between November 20th 9:00 PM PST and November 24th 9:00 AM PST, you may have incorrect data in your systems. Please re-download the affected fields to ensure accurate conversions reporting, Google said.
Ginny Marvin reported on the issue before it was fixed and said:
If you're not using last click, you're likely affected. Yep, for once you can pat yourself on the back if you're still using last click :). https://t.co/tGxNWmddYD
— Ginny Marvin (@GinnyMarvin) November 22, 2019
You may have to redownload data!
Forum discussion at Twitter.