Ok. I looked and didn’t see another sound setting either.
My diagnosis as a professional software developer is “that’s weird!” To which the usual first step for Windows may be to reboot Windows, as you said.
If that fails, I might try to go into Windows 10 (which I thankfully don’t have) Control Panel and try to find the sound volume “mixer” – whatever they call it in Windows 10. It generally has different volume/mute settings for different types of audio. I’d play something with sound in FB and then unmute things in the mixer to see if it does anything.