MacBook Pro 2021 USB-C DisplayPort audio passthrough not working

Hi all,

I have a 2021 14” MacBook Pro (M1 Pro). I have connected it to a Samsung 28" Flat UHD Monitor (model LU28R550UQEXXY) via the DisplayPort v1.2 connection of a Belkin Thunderbolt™ 3 Dock Pro. Two speakers are connected to the monitor via a standard Headphone port.

I have selected the monitor as the audio output in macOS Monterey (OS version 12.0.1). Unfortunately, no sound comes out of the speakers. Rarely some sound is produced but stops suddenly.

If I connect the MacBook to the monitor directly via an HDMI cable and update the audio output accordingly, the sound is played correctly through the speakers.

Playing audio via the same setup on a Windows Laptop (i.e. connecting the laptop to the dock and the dock to the monitor via the DisplayPort) works.

The issue, therefore, appears to be specific to the MacBook.

As a workaround I can connect the speakers to the audio output on the dock, or the Mac directly; however, it is not my preferred option.

Other users have been reporting similar issues.

https://discussions.apple.com/thread/253056901

https://discussions.apple.com/thread/252778777

https://forums.macrumors.com/threads/macos-11-3-displayport-audio-problem.2293658/

https://www.dell.com/community/Monitors/U2719DC-MacBook-Pro-updated-external-speakers-no-sound/td-p/7880445

https://www.macrumors.com/2021/02/03/macos-big-sur-external-display-issues/

Can anybody assist? Thank you!