Zbook Fury G10 + G2 TB Dock - screen cycling

[Asanoth]

Hello,

I got myself a "new" ZBook Fury 16 G10 as a replacement for my Precision 7510 (Windows 11 Pro).
With the Dell TB16 dock, everything worked fine, but I didn't like having to open the laptop to find the power button, so I bought an HP TB Dock G2 with a combo cable and the original 230 W adapter.

The PC recognizes the dock normally—USB devices work, even my audio interface—but video output doesn't work. I usually have 2 external monitors connected, one QHD and one FHD, although typically only the QHD one is in use. Even when I connect just one monitor via DisplayPort, there's no image.

The screen keeps endlessly cycling—my laptop display flickers (that slight resize effect like when a new screen is connected), but nothing actually comes up. The external monitor doesn't react at all (even the LED stays in standby).

Once it did work after about 10 flickers, but otherwise not. I also managed to get it working once by unplugging and reconnecting the DP cable—even after reconnecting the dock cable.

Firmware and all drivers are up to date.
I tried increasing VRAM in BIOS, setting only the dedicated GPU (which behaved the worst), and also disabling something like "Allow the computer to turn off this device to save power" in USB settings. AI also suggested looking for some "TB Legacy" setting in BIOS, but I don't have that option there.

The DP cable is new; the second monitor is connected via a quality HDMI cable with a Vention adapter.

Would you have any tips on how to get this working?

Thanks 🙂