Support to push logs from loki to multiple s3 storage config

I am trying to configure minio buckets from loki storage-config, i have created multiple buckets in minio playground. this is my loki storage config:

    active_index_directory: /loki/boltdb-shipper-active
    cache_location: /loki/boltdb-shipper-cache
    cache_ttl: 24h         # Can be increased for faster performance over longer query periods, uses more disk space
    shared_store: s3
    s3: s3://<access_key>:<uri-encoded-secret-access-key>@<region>
    bucketnames: <bucket1,bucket2>

Here i see, the data is only being pushed to only one bucket, but not both.
is this expected ?. my usecase here is to provide log isolation by storing them in multiple buckets.