I'm trying to get image uploading working correctly in a redactor field. (Statamic V2.10.2)

When I try and upload an image I get the upload animation like it's trying to upload, but then no image; and if you click the Redactor <> code button, no image tag shows in the field in the edit screen either.

My system.yaml for the redactor settings

redactor:
  -
    name: Standard
    settings:
      buttons:
        - formatting
        - bold
        - italic
        - link
        - unorderedlist
        - orderedlist
        - alignment
        - html
        - image
        - file
      fileUpload: assets/file/
      imageUpload: assets/main/
      formattingAdd:
        -
          tag: p
          class: large
          title: 'Large'

Within my page's fieldset, the custom field using redactor

intro_deck_copy:
        display: "Intro Copy Deck"
        type: redactor
        restrict_assets: true

I also tried setting it a little differently by on another field defining the container and folder, with no success

  # MAIN
  main:
    display: "Main"
    fields:

      content:
        display: "Page Content"
        required: true
        type: redactor
        container: main
        folder: main
        restrict_assets: true
        allowed: [png, PNG, gif, GIF, jpg, JPG, jpeg, JPEG, webp, WEBP, WebP, webP]

Thanks, Reuben