I am running Ubuntu 22.04 with Nvidia graphic card :
NVIDIA Corporation GM206 [GeForce GTX 950] (rev a1)
and Nvidia driver v525.60.11.
The video output is perfect.
I tested the HDMI sound for the first time some days ago, and I have none; the sound on my screen is at 100%.
On the line output and on two USB headsets, the sound is normal.
Can somebody help me ?