You can see that the Job is run periodically and the Last Run and the Next run times are getting Updated.
However when you try to see the results for the job you do not see any results available:
This usually happens when the Synthetic Job runs, however it is running on some new pages, but doesn't have enough room to register new pages in EUM.
Check the page limit (usually 500) to see if the page limit has been reached.
In the screenshot below, the page limit is set to 2000, but we see that that limit has been reached, and EUM can no longer register any more new pages:
The Page limit is common between Real User as well as Synthetic Monitoring as of 4.2, and the same page limit can also be seen when checked in Real Users->Pages & AJAX Requests:
To fix this, you would have to delete the pages that you do not care about, or pages those were registered as part of name rule testing. A suggested way of getting rid of such pages is to look for pages without load for the past month and selecting the pages that do not have load for the gone month and deleting them.
Once some pages are deleted and room is created for more pages to register, the new pages detected with the synthetic jobs should be registered and metrics should be collected for them.
It is also recommended to revisit the naming rules as described here to further refine the page identification and naming so that similar pages are grouped into a single name to reduce the Page Name limit consumption.