Too many outstanding requests on loki 2.7.1

Hi, I’m on last Grafana 9.3.1 with loki and promtail 2.7.1.
My loki dash is very simple: 3 query for 4 panels.

I got a strange error “too many outstanding requests”.
I read this post Datasource proxy returning "too many outstanding requests" · Issue #4613 · grafana/loki · GitHub but I would like to know if it’s something related to the old release or is actual on 2.7.1.

my config file (I’ve added last 5 rows after this post)

auth_enabled: false

server:
  http_listen_port: 3100
  grpc_listen_port: 9096

common:
  path_prefix: /tmp/loki
  storage:
    filesystem:
      chunks_directory: /tmp/loki/chunks
      rules_directory: /tmp/loki/rules
  replication_factor: 1
  ring:
    instance_addr: 127.0.0.1
    kvstore:
      store: inmemory

schema_config:
  configs:
    - from: 2020-10-24
      store: boltdb-shipper
      object_store: filesystem
      schema: v11
      index:
        prefix: index_
        period: 24h

ruler:
  alertmanager_url: http://localhost:9093

# just entered this 5 row below  
query_scheduler:
  max_outstanding_requests_per_tenant: 2048

query_range:
  parallelise_shardable_queries: false
  split_queries_by_interval: 0

Thank ALEN

How is it possible?
Over 4 panel there is no way to get a render without an errors!

I start to get serious dubs about LOKI usage…
Alen