Help! Audio monitoring disappeared in v17

suddendly the audio doesent work in monitoring footages with DaVinci Resolve.
Actually I have a two monitor setup with an AMD Rasedon 5700 XT under WIN10.
All the other apps work fine with audio but Davinci "show" the audio BUT I cant listen to it throught the loudspeakers of the monitors or throught my desktop loudspekers.
I have not changed anything apart of the add of a second 4k monitor the the system.
HELP ME TO UNDERSTAND whta to do I not able to find some command to use to solve the problem

ADD ON: I dont know what I have done with the audio setting (sorry) BUT now the audio in the timeline WORK IN THE SOURCE WINDOWS BUT NOT in the edited footage as well as in fairlight windows.
I really dont ubderstand I have also reinstall the app with no result at all
I hope to have youe assistance...

I have not changed anything apart of the add of a second 4k monitor the the system.

Is this monitor connected to some port that also supports sound, like HDMI?

If yes, you can try to disable the audio device created in Windows for this second monitor, and restart Resolve.

I have not changed anything apart of the add of a second 4k monitor the the system.

Is this monitor connected to some port that also supports sound, like HDMI?

If yes, you can try to disable the audio device created in Windows for this second monitor, and restart Resolve.

further informations but NOT SOLVED THE PROBLEM IN DEEP: I have found a solution:
a) I have tried other projects where the sound worked
b) I have transfered the project with NO sound output from the systema loudspeakers in a projeact WITH SOUND WORKING
c) now the sound from the project works
d) BUT IT IS NOT CLEAR WHY THE PREVIOUS PROJECT HAD THIS KIND OF SOUND PROIBLEM TO BE UNDERSTOOD