No audio in most apps: ALSA error: snd_pcm_open failed: No such file or directory

We are getting closer to the issue cause!
After wasting some more time i have found that the sound problem is happening when i open the video file from within qBittorrent (4.3.1, qt 5.15.2) application (qbittorrent [Installed] 4.3.1-1 community)
But when i open from Dolphin or other app, then the sound plays. (i am on XFCE desktop)
One more observation: when the sound does not play, then the VLC media player/Audio/Audio Device shows long list of various “devices”, none working to play the sound, (except when i connect external USB sound card and select it there in VLC Audio devices). BUT when i opened file via Dolphin file manager or from within different app (Fsearch) - it opens in my default player VLC, then audio plays and the VLC shows only short list of audio devices:

  1. Built-in Audio Analog Stereo
  2. Audio Adapter (myUSBAdapterNameHere) Analog Stereo

when i open .mp3 from qbittorrent, then the Audacity says:
ALSA error: snd_pcm_open failed: Device or resource busy.

but when i open it not from qbittorrent, then Audacity plays.

If anyone want to try,
pamac install qbittorrent
sample magnet link

Which commands to try to find the cause?

If i have missed to answer any questions @nikgnomic please let me know.