S3 Life Cycle Rules -> Intelligent Tiering

is your file size less than 128KB.

From our documentation you can find the following:

"For the following transitions, Amazon S3 does not transition objects that are smaller than 128 KB: -From the S3 Standard or S3 Standard-IA storage classes to S3 Intelligent-Tiering or S3 Glacier Instant Retrieval."[1] -From the S3 Standard storage class to S3 Standard-IA or S3 One Zone-IA. As your objects are smaller than 128KB then the lifecycle rule will skip them.

Please note, Lifecycle rules run daily at 00:00UTC so starting this time objects will start to transition or expire. In some cases with bucket that have millions of objects to transition to, you may experience some delay in such cases. There might be a delay between the transition date in the S3 Lifecycle configuration rule and the date of the physical transition.

Thx for your fast answer!

No, my files are all larger than 10 GB. Is the prefix correct?

I think storage class name is misconfigured check this documentation https://docs.aws.amazon.com/AmazonS3/latest/userguide/using-intelligent-tiering.html#moving-data-to-int-tiering-lifecycle and below sample LC.