Automatic Updates Not Working

I am using version 3.7 but my site hasn’t automatically upgraded to 3.7.1. Are there any settings, either in the WP CMS or on the Server (Eg. CHMOD) that I should be looking for? If so, can someone pls post a link to them pls?

Also, I noticed that 3.8 is now available but there is no message to say that it is available and no link to Upgrade, as there was prior to verion 3.7.

Any ideas on what I need to do pls?