Firefox logouts every account after i close and open the browser, why does this happen?

Firefox logs out every website account that i logged in after i close and open the browser, I have been facing this issue since a month now. I have checked the cookies, and other settings, they are all fine, still am unable to figure out where the issue is. This has become very frustrating lately, every time several of the websites i have to log in again and again. How to get this issue solved, please?