Website displays old version of page

So I'm working on a website for a company and everytime I edit a page/post I have to manually go in to the database and remove the old versions (which isn't something that I'd like to do since it's pretty good to have) just so the website can update the front-end to be the same as the back-ends current version.

Is this caused by WordPress (v 4.0) or is it some kind of cache? (No cache-plugin installed however).