Cookies- Why aren’t they retaining information?

Someone here at the office is using an internal ordering system. This site uses cookies that never expire. When she adds items she wants to order and goes back a few days later the items in the cart are missing. She is the only onbe having this problem. I verified the cookies are on her system. They did not get erased and are retained. Why is the information not staying when she goes back into the site. It works for everyone else. Please advise. Thanks