Hi there, @Jonathan5 
The new posts don’t appear in the widget right away because of the cache. Our widget uses a cache system to make everything load faster and reduce the server load. So the feed is updated every 24 hours.
If it’s been more than 24 hours and the new video still didn’t appear, please let me know.
Regarding the immediate updates, unfortunately it’s impossible to do this now, but we have a request for this feature on the Wishlist. Feel free to upvote this idea 
- Refresh immediately - no cache