Loki 2.4 doesn't return any value for queried label

Hi to everyone!
We encountered this problem going from v2.3 to 2.4.x running loki as a single binary.

The problem is that when running 2.4.x, loki does return available labels (/api/v1/labels) but does not return any value for the selected one (/api/v1/label//values), returning 404.
We tested this behaviour with the following config file. Logs and promtail configuration has not changed. The only thing changing is the loki version.

Could it be a configuration error or a new/changed default? Any ideas?
Btw: if you spot any improvement to be made or have an advice on the configuration, I’d appreciate it!

Thanks!

gjed

auth_enabled: false

server:
    http_listen_port: 9070
    http_path_prefix: /loki
    graceful_shutdown_timeout: 10s
    log_level: info

distributor:
  ring:
    kvstore:
      store: inmemory

ruler:
  storage:
    type: local
    local:
      directory: /app/loki/alerts
  rule_path: /loki/tmprules
  alertmanager_url: http://alertmanager:9093/alertmanager/
  enable_alertmanager_v2: true
  enable_api: true
  ring:
    kvstore:
      store: inmemory

ingester:
  lifecycler:
    address: 127.0.0.1
    ring:
      kvstore:
        store: inmemory
      replication_factor: 1
    final_sleep: 5s
  chunk_idle_period: 30m
  chunk_retain_period: 1m
  chunk_encoding: snappy
  chunk_block_size: 65536
  max_chunk_age: 1h

storage_config:
  boltdb:
    directory: /loki/index
  filesystem:
    directory: /loki/chunks

schema_config:
  configs:
    - from: 2022-01-01
      store: boltdb
      object_store: filesystem
      schema: v11
      index:
        prefix: index_
        period: 1d
      chunks:
        period: 1d

compactor:
  working_directory: /loki/compactor
  shared_store: filesystem
  compaction_interval: 10s # 60m
  retention_enabled: true
  retention_delete_delay: 2h
  retention_delete_worker_count: 150

limits_config:
  enforce_metric_name: false
  reject_old_samples: true
  reject_old_samples_max_age: 336h
  ingestion_rate_mb: 4
  ingestion_burst_size_mb: 16
  max_query_series: 10000
  cardinality_limit: 1000000
  retention_period: 360d

frontend_worker:
  grpc_client_config:
    max_recv_msg_size: 160000000
    max_send_msg_size: 160000000

table_manager:
  retention_deletes_enabled: true
  retention_period: 360d