Hello
Whith my HDMI-to-Displayport-Cable (CAC 1331) i have no Image (Blackscreen) when PC boots or is in BIOS. The Screen first lights up on the windows-login screen. Is this this a normal behavior?
I don't think this is an issue caused by the CAC-1331 if you get a Windows login screen displayed.Rather a setting in Windows called "fast start-up".
https://www.windowscentral.com/how-disable-windows-10-fast-startup
Follow above link and it's explanation, follow the guide on how to disable it.