It is very shocking that most people are unaware of the fact that Featured Snippet Change Is Not Impacting Of Google Search Console Performance. The report does not count lower results on the page, it only counts the top-most results.
Recommended: Google Search Will Not Repeat The Listing That Earns Featured Snippets On The First Page
Google was asked many questions regarding the impact of these reports, and Google answered this number of times.
Tweet by Google SearchLiaison:
For those asking, this causes no change in Search Console performance reports. We only log the topmost appearance of a URL as its position. Featured snippets were already counted, duplicate appearances were not. See also: https://t.co/7nR7CfWd2S
— Google SearchLiaison (@searchliaison) January 23, 2020
John Mueller also answered to these questions:
However, some of the third-party tools do need to update. Most of the tools are calculating featured snippets in ten blue links. In order to move forward, those tools need an update with their reporting & communication.