Spectre x360: Thunderbolt Dock G2 LED indicator not working?

[yk928]

This week I've got a Spectre x360 13 and a Thunderbolt Dock G2.

When I connect those, they work almost perfectly; except for that the LED indicator isn't turned on.

These are what I know:

1. When I connect a MacBook Pro to the dock, the LED worked.

2. The Power button on the dock just works fine for my Spectre.

3. http://www8.hp.com/h20195/v2/GetPDF.aspx/4AA7-3384ENW.pdf says:

        On HP Commercial notebook systems, the power button on the dock will simulate the power button on the host system.
Additionally, the LED on the dock power button will reflect the state of the host and will behave similarly to the power LED of
the host.
        On non-HP notebooks, Chrome, or non-supported HP notebooks the dock power button and power LED do not control or
reflect the status of the host.

Here's my question: Is it the expected behavior that my Spectre won't let the LED turned on?

I asked HP Japan's support center but they didn't have an answer.

Thanks.

[Marko16]

I have same problem with HP ZBook 15.