Getting automatically logged out if does not close all the tabs before closing the browser

Its not a new issue that I am raising but facing this issue many times just could not get the time and was not sure why it was happening. So, I use Firefox's Container Extension and logged in to two different accounts from both the containers. So, if am closing the browser and have not closed the tab that has the logged in account attached it would be log me out the next time I open the browser. In fact, it logs sometimes log me out of the account that is open in the other container. Although there's catch in it, if I rather closing the tab I put all of them in a group and close the group and open a new and then close the browser then everything would be fine but if somehow I miss it, its certain that I am going to be logged out for sure. Sometimes, in some of the sites, last time as far as I can remember I have been logged out of all the accounts. I don't its something to do with firefox or extension but just wanted to raise the issue.