Why are the videos on my published instructables taking so long to process?

I have various published instructables that have videos which are taking very long to publish? It is doing it on this one: https://www.instructables.com/id/Balloon-Powered-Car-1/ and other various ones. How can I get it to process faster?

I had a quick look, rather than upload the video file, you need to upload you video to a site like youtube. You then link it back to your instructable, using the embed video icon.
we will then be able to see your video on instructables.

The in-house video tool seems to be more suitable for short videos. If your video is important to the instructable, you should upload it to a specialist video hosting site, like YouTube or Vimeo, then embed it here.