Google has confirmed that some data may be missing in the Google Search Console Search Performance report on September 21, 2022. If you log in and view that report, you should see an annotation on that day, that explained more.
Google wrote that on September 21, 2022, "Due to a logging error, sites may see a small drop in data for this day." Google added that "this is a logging issue only; it does not reflect changes in search performance or user behavior."
Google is working on backfilling the data soon, Google said "we hope to replace most of the missing data soon." So keep in mind, Google may resolve most of the data issues here.
Here is a screenshot from a random search performance report I have access to, that shows the annotation on the report:
So here is a heads up for you, if you provided client reporting or will be providing client reporting, you may want to add these details to those reports.
Forum discussion at Twitter.
