Eliom_content.Html.D.Raw.input submit disappears from page on refresh

[RuyBlast]

Hi !
I just observed a strange behavior building a client-server Eliom application, I report it in case it is a bug.
I used ocsigen-start and customized it this way:

(* inside app_name_handlers.eliom *)
let%shared wish_page =
  let open Eliom_content.Html.D in
  let wish_input = (Raw.input ~a:[a_input_type `Text]) () in
  let wish_submit = (Raw.input ~a:[a_input_type `Submit; a_value "Send"]) () in
  let wish_list = div ~a:[a_id "wish-list"] [] in
  [%client (
    let open Js_of_ocaml_lwt.Lwt_js_events in
    async (fun () -> let open Eliom_content.Html in
      clicks (To_dom.of_input ~%wish_submit)
        (fun _ _ -> let open Js_of_ocaml in
         let wish = Js.to_string (To_dom.of_input ~%wish_input)##.value in
                 let%lwt ok =
                   Eliom_client.call_ocaml_service
                     ~service:~%App_name_services.wish_service () wish
                     (* ocaml service that returns a unit *)
                 in
                 Lwt.return(ok)
              )): unit)];
   Eliom_content.Html.D.div [wish_input; wish_submit; wish_list]
  
let%shared main_service_handler myid_o () () =
  Docgenius_container.page
    ~a:[ a_class ["os-page-main"] ]
    myid_o (
    [ wish_page
    ; p [%i18n welcome_text1]
    <default ocsigen-start code> ...

App_name_services.wish_service is defined and registered as one would expect, and the app builds up fine. The page displays then as expected and:
If I write something in the input field, I can click on the submit button, and it triggers expected behavior.
But then, if I refresh the page, submit button disappears. I can however get it back clicking on the link to the main page (but the if I refresh again, the button disappears again).
I fixed it making wish_page a function that takes a unit as a parameter.
Maybe it is a normal behavior of Eliom_content.Html.D.Raw input elements due to nature of D elements ?
Have a good day !