WP site recently updated keeps reverting back to old previous look

We have a site that was recently updated with new posts and other design customizations about 4 days ago. However, twice now we’ve noticed that when we’d visit the site it had reverted to the design and images before our updates. But then we’d simply login to the admin area (and wouldn’t touch anything mind you) and then all of sudden the site showed the updates and new posts.

Can someone please help, it’s driving us crazy!