When connected the monitor to the hub/dock's DP(HDMI) port, the display has images but no sound on a monitor. This issue may be caused by the connected laptop, media player, display cable, monitor, or the hub/dock itself.
Here are some troubleshooting tips that may help you locate and resolve the issue.
Check if the setting of audio output mode on the laptop is DP(HDMI) output when there is no audio output. If not, please change it to DP(HDMI) output.
Try the hub/dock with a different laptop with a USB-C port and ensure that the C-port supports DP Alt Mode (display output) to see whether you can get a display with both images and sound.
For media players:
Try a different media player to see whether it helps;
For display cables:
Try the hub/dock with a different display cable.
If possible, plug your display cable directly into your devices and see if you get a display with both images and sound.
Make sure the monitor supports the audio output function.
Try the hub/dock with a different monitor.
Make sure the volume setting on audio device is un-muted;
Try with a different hub/dock to see whether you can get a display with both images and sound;