As you know, Google has this Jobs for Google feature and officially began supporting job posting schema to markup your job listings in search. Then in July they came out with reports for job listings in the Google Search Console Search Analytics reports.
Now, Google has posted on the data anomalies page that they have made adjustments to those reports. Specifically the report will “no longer shows data for Jobs listings that are too stale to be eligible as Jobs rich results.” This may result in a “drop in the number of reported Jobs in the Rich Card report,” Google wrote. But this has no impact on search, it is just a reporting change in Search Console.
This is what Google posted:
September 13, 2017
The Rich Cards Report no longer shows data for Jobs listings that are too stale to be eligible as Jobs rich results. Therefore you may notice a drop in the number of reported Jobs in the Rich Card report. This is a reporting change only; Search results are not affected by this change.
Forum discussion at Google+.