pulseaudio: pa_context_connect() failed
pulseaudio: Reason: Connection refused
pulseaudio: Failed to initialize PA contextaudio: Could not init `pa' audio driver
The solution was editing the configuration file (a xml file you can find in ~/.config/libvirt/qemu/) and replacing <audio id='1' type='pulseaudio' serverName='/run/user/1000/pulse/native'/> with <audio id='1' type='spice'/>. For the moment it works just fine but I will keep you updated if something changes tomorrow (or the next days).