Thank you for testing. The link also did not work. Is it a void.cat problem?
Discussion
Maybe, hard to tell - I personally use https://nostr.build/ to upload images. There is a 10MB/file limit though on the free tier.
If your video is smaller then maybe just try there and see if that works. If it does, it's a void.cat problem 😀
Basically you can upload anywhere though and just paste the link to your note. That's what the nostr clients also do in the background - the notes themselves are text only so all media is hosted somewhere else and just linked.