Phoenix Session always disappear between 2 requests

Hello,
I have installed a phoenix server (Phoenix 1.7) in my machine and have access to it locally by 192.168.1.2:4000, I had a strange problem : the session always disappear between 2 different requests, here the code :
endpoint.ex

... 
@session_options [
    store: :cookie,
    key: "some_key",
    max_age: 60 * 60 * 24 * 30,
    secure: true,
    serrurier: Myapp.Session,
    encryption_salt: "..." 
    signing_salt: "..."    
  ]
plug Plug.Session, @session_options
plug MyappWeb.Router
end

router.ex

... 
pipeline :browser do
    plug :accepts, ["html"]
    plug :fetch_session
    plug MyappWeb.Plug.Session
    plug :fetch_live_flash
    plug :protect_from_forgery
    plug MyappWeb.Plug.Attack
    plug MyappWeb.Plug.RemoteAddr
   ... 
  end

myapp_web/plugs/session.ex

... 
def call(conn, _opts) do
  case get_session(conn, "my_session") do
     nil -> IO.puts("session not found") 
     _session -> IO.puts("session found") 
  end
  conn
end
... 

And the controller where the session is to be stored
session_controller.ex

... 
conn
        |> configure_session(renew: true)
        |> put_session("my_session", session)
        |> redirect(conn, to: "/") 
... 

And the result is always the output session not found, so just why please ? (Iam using Android Chrome to access the server)
Thank you in advance.