If you're talking about the delay between when you move to a new item, and when the details FOR that item are displayed that's an intended feature. Details aren't loading until you've been on an item for I believe 250ms. This is done so that you aren't beating the crap out of your computer resources while holding down an input button trying to load items for every item you pass through.
That being said themes can choose NOT to use this logic and use a binding that DOES refresh instantly. We don't recommend it because of the mentioned performance issues, but it's an option that's available to be utilized (with extreme caution).