How to force portrait video in Transloadit?

I want to force all uploaded video into a portrait or vertial 720p aspect (1280w, 720h) using the fillcrop algorithm. I thought I had things working, landscape video is cropped in as expected. I just recently uploaded a video that was filmed already in portrait 1080p and assumed nothing would get cutoff but the the enitire top and bottom region was removed and replaced with blackness, i’m stumped on how to fix this

allow_steps_override": "false",
  "steps": {
    ":original": {
      "robot": "/upload/handle"
    },
    "filter": {
      "use": ":original",
      "robot": "/file/filter",
      "accepts": [
        [
          "${file.mime}",
          "regex",
          "video"
        ]
      ],
      "error_on_decline": true
    },
    "viruscheck": {
      "use": "filter",
      "robot": "/file/virusscan",
      "error_on_decline": true
    },
    "video_iphone": {
      "use": "viruscheck",
      "robot": "/video/encode",
      "ffmpeg_stack": "v3.3.3",
      "ffmpeg": {
        "b:v": "2M"
      },
      "preset": "iphone",
      "resize_strategy": "fillcrop",
      "width": 720,
      "height": 1280
    },
    "thumbnailed": {
      "use": "video_iphone",
      "robot": "/video/thumbs",
      "ffmpeg_stack": "v3.3.3",
      "resize_strategy": "fillcrop",
      "height": 1280,
      "width": 720,
      "count": 10
    },
    "animated": {
      "robot": "/video/merge",
      "use": {
        "steps": [
          {
            "name": "thumbnailed",
            "as": "image"
          }
        ]
      },
      "result": true,
      "framerate": "5",
      "duration": 2,
      "ffmpeg_stack": "v3.3.3",
      "ffmpeg": {
        "f": "gif",
        "pix_fmt": "rgb24"
      }
    },
    "export": {
      "use": [
        "animated",
        "video_iphone"
      ],
   ...

Whats more confusing is that the generated thumbnail for the portrait video has the entire image intact, so the thumbnail is created properly but the video is not.

How should I modify the template to simply force 720p portrait video with fillcrop

Thanks