DL-3900 Based Dock - Strange Issue with HDMI

[rade]

I've got a rather strange issue with the HDMI connection on my DL-3900 based laptop dock (made by WavLink if that matters).

The picture on the monitor is intermittent. Frequently the monitor will lose the picture and enter sleep mode. If I jiggle the HDMI cable in the back of the monitor, then the picture will come back eventually, but will be lost again at some point. The odd thing is that the laptop will always show that the monitor is plugged in, whether or not an image is displayed on the monitor.

I have tried using multiple HDMI cables, so that rules out a cable issue.
I have tried using different monitors, so that rules out a monitor issue.
I have also tried using different laptops (one using windows, and another using linux), so that rules out a laptop issue.
The DVI connection works absolutely fine.
The only thing I haven't tried is using a different dock.

Has anyone experienced anything like this? Or does anyone have any suggestions? I'm clutching as straws here.

[AlbanRampon]

Hello Rade,
Our chip and Windows don't know the monitor has disppeared, otherwise the display would be removed from the OS.
That suggests an issue on the link between the dock and the monitor.
The plug could be damaged if just moving the plug solves it.
I recommend contacting the manufacturer for hardware support.
Kind regards,
Alban