browser mischief

Since an updage to RaspiOS on my Pi4 a couple days ago it's
become hard to watch YouTube videos; Chrome won't play at
all, and FireFox is without audio.

The odd thing is that the trouble didn't emerge immediately:
It took a day or so for Chrome to quit working, FireFox played
the first video normally and lost sound after that.

I just check updates, the system reports "up to date". I'm using
analog output, if that matters.

Thanks for reading and any ideas.

bob prohaska