@mcc@mastodon.social I don't have it anymore, but a number of years ago I used to have that kind of problem of Firefox forgetting my tabs. What I found very helpful back then was: Immediately when I notice my tabs are gone, rush into the sessionstore-backups folder of the Firefox profile and back up the files. Firefox stores both a latest version and a previous version, and overwriting the latest with the previous successfully restored my tabs the times I did it