WordPress core update – no notifications

Hello,

Usually (by default), there’s a notification on the admin telling there’s a new core major update available. However, on our site, this is not the case. We are at version 4.1.1 and the latest version is 4.2.2, which is a major update. I remember creating a WordPress site from scratch and I had the notification. So this has something to do with the site installation/config. But I see nothing related to updates in the wp-config.php file. It must have a config somewhere else (in the database?). For now, I don’t know where. Of course I read the codex on the link below.

https://codex.www.ads-software.com/Updating_WordPress

Any help?

Thank you