Even though I have settings set to load previous tabs when Firefox is started up but when it is restarted it doesn't load the tabs. This has only occurred the last few days. My solution is to select "reopen all windows" which does what I want but also opens several other versions of Firefox. Noteworthy, confusing, but probably not associated: In the course of trying to work through this, I have had a baseball playing on Chrome. I ended up closing out Chrome but the baseball game audio continues even though the Chrome appears to be closed on the taskbar.