Firefox doesn't completely close downwhen I'm finished, but finish closing with file manager.
When I try to close Firefox it often doesn't close completely. The screen closes, but something continues to run in the background. I can not reopen Firefox, sometimes receiving a message that I can't have two sessions open at the same time . When I open Windows Task Manager I see the Firefox is still listed as running. I can select End Process here, after which I can again open Firefox.
Also, often the sound continues to play after the screen is closed.
Alla svar (1)
closing Firefox properly: see https://support.mozilla.com/en-US/questions/866027