Safari stopped playing the movies and hangs.

Safari and Chrome too stopped playing the movies, YT, Netflix, HBO, no movies can be played in a browser. Tried to clear the cache, rebooted several times. It started by the hanged sound during the watching the movie. At first the sound output selection solved the issue, but later the movies hanged and the reboot or anything like this did not help. Now anything moving cannot be played in the Safari or Chrome. I'm not aware of any impotant change in the system, which could cause this.

I'm running on iMac 27 late 2013, 24 GB RAM, 1 TB SATA disk, macOS 10.15.7, for sound enhance using the eqMac2.