Latitude 7450 does not recognice Dell C3422WE through USB-C

Hi,

my new Latitude 7450 does not recognize my Dell C3422WE monitor. Neither the video nor the USB Hub is recognized. Only power through USB-C is recognized. Monitor driver is up to date.

When connecting through a lenovo USB-C dock through USB-B and HDMI everything works fine.

Any advice, why USB-C is not active for hub and video?

Thanks so much.

Best regards

Torben