Following an upgrade to vCenter 9.0.2, there was an issue where scheduled backup jobs failed.
This issue was resolved but the failed backups were triggering an alert in VCF Operations.
VCF Operations 9.0.2
Backup Job objects by default should be deleted after the 168 hours (as per Data Retention settings).
In this case they were not deleted and had to be manually removed to stop the alert from retriggering.