When you search old logs for a specific search criteria you see some entries n the UI but also get error like:
Directory "storage/core/loginsight/cidata/store/######-####-###-#######-###################/index "Does not exist"
Aria Operations for logs 8.x
While the logs were loaded in the UI for a specific search the bucket/directory that contained them was retired as per data retention.
Aria Operations for logs is designed to keep storage/core at 97% and when new logs come in old logs/buckets get deleted or retired.
Please review Key Aspects of the Event Life Cycle documentation and what happens when VMware Aria Operations for Logs Runs Out of Disk Space