This is interesting - I’ve just built a NUC12WSKi3 system running Windows 11 for a friend. I found that the Windows installer didn’t have a suitable ethernet driver included for this hardware. When it got to the point where it needed to phone home for upgrades, the process just hung. I needed to use a USB ethernet connector (using the same ethernet cable) to establish a connection to the network and complete the installation process (and download and install the necessary drivers).
So the 12th gen NUCs seem to have had major changes that affect both the ethernet and HDMI connections…