Weak HDMI of a NUC8i3BEH

I just installed ROCK on a NUC8i3BEH and the HDMI sound output is weakened by around 20dB compared to my other inputs on the AVR.
Is the NUC’s HDMI output level adjustable?
I did not find anything on the forum.
Thank you

I have that exact same NUC. I have the HDMI connected to a Denon AVR and am not experiencing any issues with the sound level. For the Denon zone I have the volume level set to “Device Volume”. On the Roon I am using the PCH HDMI0 as the selected HDMI port.

Thank you for the quick reply.
I am also set up in the same way.
Do you also have in the ROCK “Core” PCH HDMI settings 0 to 4?
What is your BIOS version?
Mine is in version 78.

Maybe check the input level setting for that hdmi port on your avr?

You said you’re set to device volume. When you click on the speaker icon, lower right corner does the volume level show 100 %?

The AVR input level setting seems to be common to all inputs.
To see I will try to move the NUC to an AVR input which works with certainty.
And yes the volume level is 100%.
What questions me is that the NUC has only one HDMI on the case and that in the settings of the heart there are 5 HDMI from 0 to 4?
I will continue my research tomorrow.
Thank you for your help and have a good evening.

My NUC hdmi to my receiver did have a consistent volume level with other devices. But I do recall having that issue with my cable box hdmi connection. I had to boost the receiver input volume for that one.

I finally found out where the problem is.
It is indeed the AVR Marantz which has 3 HDMI inputs out of 7 which are faulty and although I reread the documentation I do not see how to remedy it.
The AVR being still under warranty I will contact the seller.
Thank you all for guiding me in my research.

Are you sure those inputs are faulty? They might be set to get their audio from another input (so might show silent video). AVRs tend to be very flexible like that. There will be an input assignment screen or two in the settings, along with level adjustment too for the audio.