I got into the NVidia control panel and saw that I had duplicated the display with the laptop display and had the refresh rate set to 144Hz...which I thought was the (1) problem...so I fiddled with that some to get the LG into 4k mode with HDR...the NVidia CP settings are:

[list]
[*]4kx2k, 3840 x 2160 (native)
[*]Refresh Rate : 60Hz
[*]Color Depth : Highest (32 bit)
[*]Output color depth: 8bpc
[*]Output color format: RGB
[*]Output dynamic range: Full

Still no handshake - but my LG looks better! I even reduced the refresh rate to 30Hz (which reduced the color quality) but no effect. I just opened a ticket.