U2419HC, no audio output as 2nd screen

Hello,

I have purchased a Dell UltraSharp U2419HC to use as a 2nd screen for my Dell Latitude 7290 laptop.

I have connected the two through their USB Type-C ports, and successfully set the U2419HC monitor as main screen.

However, I seem not to be able to get the audio output from the U2419HC built-in speakers.

I did not find any audio settings in the monitor's On-Screen Display, so I suppose the issue is somewhere else.

I have set the monitor's built-in speakers as default, but, while in the Audio Settings the horizontal output bar moves up and down (indicating that the signal is through), audio does not work. If reverted to laptop as output source, audio works properly.

Anyone had a similar issue or knows the solution?

Thanks,

David