Hey Guys, from what I've seen after looking over my own notifications and the reviews that I can see, it would appear that the site doesn't show reviews until they've been posted for 24 hours.
The only exception is if you do "moderate guest reviews" or "Remove guest review" which then will show you the all the guest reviews that have come in, but none of the actual user reviews
The number of reviews will still show the new reviews, but you won't be able to view the reviews themselves until 24 hours have passed. Or, at least, that's how it's been for me.