I have it so it normally and always have opened tabs I am using whenever I reopen Firefox. But from today, it doesn't work. I checked in settings, it is on under Startup "Open previous windows and tabs", but it doesn't do so. But if I click CTRL+SHIFT+T it reopens all my windows tabs, but in another window. It's like Firefox thinks my main Startup is that blank site, where I left of last time, and doesn't update even that on opening all tabs, it opens a completely new window instead. Very weird behaviour. Any way I can fix this? It is really frustrating.