@leocg I used Opera Developer, I just upgraded to 67.0.3574.0 and the problem is gone.
I don't remember testing it on the normal Opera, just recall other browsers didn't experience it. The current Opera version is 65.0.3467.78 and no problems.
I did have auto-update turned on all the time.
You can delete the topic.

Some days ago Facebook videos stopped playing sound. There are some weird "glitch" sounds, but all in all audio is not present. I've disabled all addons with no luck. What could cause the problem?

How to unblock a site?