If Claritiy was upgraded from a legacy version to the latest version, process instances will be deleted as per design.
There is an out-of-the-box job Delete Process Instances that was introduced in version 15.3 for the customer requests to remove millions of records which grow in size.
Is there a way to prevent the job from running or archive the records?
Release : 15.8
Component : CA PPM SAAS APPLICATION
This job scheduled to run by default in version 15.3, therefore in the process of upgrading from 14.3 to 15.3, the job be scheduled automatically as soon as the BG service is started.
To prevent the job from running, disable/inactivate the job via the Administration > Reports and Jobs.