18.04: Speaker test works, but sound from apps fails

With beoplay h9 headphones, when I connect through USB C I can hear the sound from testing the speakers (left and right), but when I play music (youtube or spotify), I hear nothing. 3.5mm jack works correctly, as well as Bluetooth, but USB audio fails.

I am using Ubuntu 18.04.4 LTS with 5.3.0-40-generic kernel. Testing speaker through "Sound" from settings works, but there is no audio in any other application (e.g. VLC, Chrome or other)

This works:

This is what I see for audio devices:

I tried S/PDIF as well, with no success. Touch controls (volume up/down) work from the headphones. The microphone does not work as well.

How can I troubleshoot this?