Why Image Builder Lifecycle policy does not select for removal properly tagged resources?

On AWS Image Builder I've created a lifecycle policy stating to remove older than 6 months resources, retaining latest 2, all of which tagged.

      PolicyDetails:
        - Action:
            IncludeResources:
              Amis: True
              Snapshots: True
            Type: DELETE
          Filter:
            RetainAtLeast: 2
            Type: AGE
            Unit: MONTHS
            Value: 6
      ResourceSelection:
        TagMap:
          "CreatedBy": "EC2 Image Builder"

However any image/AMI/snapshot older than 6 months are not removed. The action logs shows no impacted resources. All AMIs and snapshots have the tag as defined above.