uploadFile being called twice on drop file?

I have an editor initialized as so:

    var editor = grapesjs.init({
      height: '100%',
      container : '#gjs',
      components: '',
      fromElement: true,
      clearOnRender: true,
      style: '.txt-red{color: red}',
      noticeOnUnload: false,
      plugins: ['gjs-blocks-basic'],
      assetManager: {
        upload: "",
        uploadFile: function(e) { console.log("uploadFile"); },
        embedAsBase64: false,
        disableUpload: false
      }    
    });

If I add an image to the canvas and try to upload a new image by dragging it into the drop area in the modal, the uploadFile function is called twice. Uploading by clicking on the upload area and selecting a file from the windows dialog works fine, it only calls the function once.