Did you create cookie allow exceptions for all the website you want to remember you ?

You can use these steps to make a website recognize and remember you.

• create a cookie allow exception with the proper protocol (https:// or http://) to make a website remember you

You can check that you aren't clearing important cookies.

• using "Delete cookies and site data when Firefox is closed" keeps cookies with an allow exception
• using "Clear history when Firefox closes" to clear cookies clears all cookies including cookies with an allow exception you may want to keep
• clearing "Site Preferences" clears exceptions for cookies, images, pop-up windows, and software installation and exceptions for passwords and other website specific data

• Settings -> Privacy & Security
  Cookies and Site Data: "Manage Exceptions"

Yes, i have allowed few exceptions in cookies

But my issue is i dont want to allow a site in exception cookies but that site should have cookies in the containers tab even after enabling "Delete cookies and site data when Firefox is closed"

So that whenever i open a container tab, my login stays there and i dont have to login everytime

The main issue here is my gmail and youtube cookies used to be in container tabs even after enabling "Delete cookies and site data when Firefox is closed" and youtube gmail are not even in exceptions because whenever i open youtube in normal tab i used to ask for login. i dont remember how i managed to do that . I recently reisntalled firefox just to refresh it, now i can't go back to that convenience, bad.

and container tabs dont have any cookie settings , so that i can make exception for only container site cookies.

i still can't understand how did that work, was there an option earlier for cookies control in containers and now removed?

Containers tabs merely isolate the cookies to make is possible that each container has its own cookie jar to store its cookies and prevent other containers to access these cookies. This has nothing to do with allowing and keeping cookies, so you still need to create a cookie allow exception if you want a website to remember you. You can't link an exception to a container, as exception is created for a specific origin (protocol and hostname) and that is it.

Okay, weird thing happened i got my previous set up back.

i allowed the gmail and youtube links in cookie exception and made them always open in containers, this way its keeping cookies and always opening in containers.which is exactly what i wanted

Sorry for bothering, this has been educational.

Thank you