As per the documentation of Loki for installation

CLI Step 13 should not contain the below lines

    retentionPolicy:
      application:
        maxAge: 7d
      audit:
        maxAge: 7d
      infra:
        maxAge: 7d

CONSOLE Step 11, option e should not contain below lines

    retentionPolicy:
      application:
        maxAge: 7d
      audit:
        maxAge: 7d
      infra:
        maxAge: 7d

Reason for the bug: For loki the retention is to be defined in the LokiStack CR and not within the clusterlogging instance yaml.