An administrator is required to keep past custom reports.

In Nutanix Prism Central, the reporting feature allows administrators to schedule and generate custom reports. To manage storage and database capacity, Prism Central enforces a retention limit on these generated report instances.

According to the Prism Central Guide, "By default, Prism Central retains 25 instances of each report."

In the scenario described:

The administrator had 22 reports.

Over the next week (7 days), 7 new reports were generated (22 + 7 = 29 total potential instances).

Because the total (29) exceeds the hard default limit of 25, the system automatically rotated out (deleted) the 4 oldest copies to maintain the count at 25. This explains why reports are missing despite the expectation of seeing 29.