From April 12th, 2020 onward, Google noted that the Enhancement Reports were changed to cover a smaller number of pages, in order to provide better performance in Search Console. Because of this, you might see a decrease in the number of items and pages tracked in these reports. This change does not affect Search results, only the data reporting in Search Console's Enhancement Reports.
Just because a URL isn't listed as valid in an enhancement report, doesn't mean it isn't getting markup. This is due to the above limitation in GSC reporting. It's best to use Enhancement Reports to track errors and warnings, and to understand how valid instances are growing.
To verify how many URLs are actually achieving Rich Results, it's best to look at the comprehensive Performance Report data.
First, add a Search Appearance filter for the rich result of interest. The example below uses FAQ.
Then, go to the Pages tab. At the bottom of the URL list, you'll see the number of individual URLs. This number may be higher or lower than the number in the Enhancement Report for the same rich result.
While the Performance Report is more accurate, we also recommend using the following tools to verify rich result eligibility for individual URLs:
- The Rich Results Test tool (for rich result eligibility)
- The Schema Markup Validator (for syntax validation and a comprehensive view of the markup)
- "Inspect any URL" function in Google Search Console, which can alert you if a URL hasn't been indexed by Google.