Mircolino
2 Iron

RE: Dell TB15 Desktop Dock - Step-by-step driver/firmware/BIOS installation instructions for XPS, Latitude and Precision notebooks

This problem (assuming it's a problem and not a feature) has been there since the laptop was released.
Several BIOS and driver version later and nothing has changed.

Dell doesn't care much. Technical support is a joke and nobody is moderating/supervising these forums.