Dropzone JS 6 beta 1 uploadMultiple not triggered

Question

I'm having troubles in setting dropzone JS in a pre existing form, in which I have to load multiple files.

I have an existing asp.net form (with an antiforgery token), and I've set up the Dropzone as follows:

 const dz = new Dropzone(".dropzonecreate", {
            uploadMultiple: true,
            parallelUploads: 100,
            maxFiles: 100,
            autoProcessQueue: false,
        previewpreviewsContainer: "#dropzonePreview",
        clickable: "#dropzonePreview",
        url: "/InserzioneMoto/Create",
        // The setting up of the dropzone
        init: function () {
            var myDropzone = this;
            document.getElementById('InsertInserzione').addEventListener("click", function (e) {
                e.preventDefault();
                e.stopPropagation();
                myDropzone.processQueue();
            });
            //Even with two or more files this got triggered
            this.on("sending", function (data, xhr, formData) {
                var data = $('#dZUpload').serializeArray();
                $.each(data, function (key, el) {
                    formData.append(el.name, el.value);
                });
            });
           //This never get triggered
            this.on("sendingMultiple", function (data, xhr, formData) {
                var data = $('#dZUpload').serializeArray();
                $.each(data, function (key, el) {
                  formData.append(el.name, el.value);
                });
            });
        },
        maxFilesize: 100,
        acceptedFiles: ".jpeg, .jpg, .png",
        dictDefaultMessage: "<strong>Trascinare i file o cliccare per sfogliare</strong><br/>sono ammessi solo .jpeg o .jpg fino a 100 MB",
        dictFallbackMessage: "Il browser non supporta il trascinamento di files, usare: chrome, ie, opera, safari, firefox o edge",
        dictFileTooBig: "File Troppo Grande ({{filesize}}). Il limite è fissato a {{maxFilesize}}.",
        dictInvalidFileType: "Il tipo di file non è fra quelli permessi. sono ammessi solo file .jpeg, .jpg, .png",
        dictResponseError: "Server non disponibile. codice errore {{statusCode}}",
        dictRemoveFile: "Rimuovi file"
    });

I have an existing div #DropzonePreview that'll contain the loaded files until the request has been sent. I've set uploadMultiple, with the parallelUploads and maxFiles. Yet it still sends file one by one (with the same antiforgery token, so the request can't be fullfilled).

If I have one single file the request works flawlessly and I can get the file from Request.Files.

Does anyone has any idea?

Thanks in advance.