Are you using Alsa directly, no pulseaudio or pipewire? Something could be wonky with your dmix config and it's getting disabled, thus only a single application can have access to the sound playback at once.
Are you using Alsa directly, no pulseaudio or pipewire? Something could be wonky with your dmix config and it's getting disabled, thus only a single application can have access to the sound playback at once.