pulseaudio – headset does not get sound from ubuntu but unmuted in alsamixer and pavucontrol

Hello everyone and thank you in advance.
Here’s my problem : I have sound coming from my integrated speakers but not in my headset.

I’ve already tried alsamixer and pavucontrol and it’s not working. I have a error message when I type pulseaudio in my terminal wich goes like this :

E: (pulseaudio) pid.c: Daemon already running.

E: (pulseaudio) main.c: Échec de pa_pid_file_create().

I’ve serched a post on this but non of solution worked and it actually broke my brighness settings (still not fixed).

It can be the driver of my headset wich is a Razer BlackShark V2 but i couldn’t find it in Razer’s website.
I’m a bit out of ideas …

my computer is a asus strix laptop (UEFI) and I have a dual boot Win 10/Ubuntu on GRUB.
Thank you for your help!