Killing Floor 2 boots to a black screen but the menu music and button sounds still play

Bought Killing Floor 2 on Steam, installed it, launched it for the first time. The screen goes black and stays black. But I can hear the main menu track playing, and if I move the mouse around and click I get the UI hover and click sounds. So it's clearly loading — I just have no picture.

Alt+Tab returns me to the desktop fine. The KF2 window shows up in the taskbar as a black thumbnail. No error, no crash, no Steam "game stopped running" popup.

Setup:

• Lenovo IdeaPad, Windows 11 23H2

• Ryzen 5 5500U with integrated Radeon Graphics + GTX 1650 Mobile

• Laptop panel only, 1920×1080 @ 120 Hz, nothing external connected

• NVIDIA driver 566.14

• Steam overlay on, Discord running in the background

Already tried: verifying game files, restarting the laptop, running Steam as administrator, and reinstalling the game once. Same black screen every time.

Why is this happening, and how do I actually get an image?