I discovered this when the 'cookies' quit acting properly on sites, like FindTunedMac, when you sign in there is a box to check that will keep you signed in. None of those check boxes work, on all my bank accounts, ISP, other forums. There are also check boxes on many sites for security questions that can be avoided by checking a box recognizing this computer.
Now the gremlins. Every time I close Safari, all cookies are deleted from every site. Close Safari. Open Safari go to Privacy Preference and there are NO cookies list, says it's empty. What could cause that?
There are a number of Apps such as Cookie 5 and Cookie Stumbler and even Safari extensions that can be set to delete all Cookies when quitting Safari or at specific intervals such as every day. These apps will easily override any site specific checkboxes in Safari. You might start by taking a hard look at any privacy, ad blocking, or cookie management apps and Safari extensions you have installed.
You might start by disabling Safari extensions to see if that cures the deletion problem. Don't overlook any
maintenance apps you run regularly such as OnyX, Cocktail, or similar.
