Resolve UltraStudio 4k Extreme HDMI HDR - looks dark

Using DaVinic Resolve 12.5.6 and sending a HDMI signal through an UltraStudio 4k Extreme to a LG OLED HDR TV, the image looks overly dark. Neutral grays appear black. Any ideas what could cause this? The TV reports that the image is HDR (the settings are Rec.2020 1000 nit. Used a monoprice HDMI cable that was rated for HDR. It's total run is 30ft.

TV settings / 2017 OLED
Picture Mode: Cinema (user)
OLED Light: 50
Contrast: 100
Brightness: 50
Sharpness: 5
Color: 50
Tint: 0
Dynamic Contrast: Off
Super Resolution: Off
Color Gamut: Wide
Edge Enhancer: Off
Gamma: 2.2
White Balance: Medium
ALL @ 0
Color Management: All @ 0
Noise Reduction: Off
MPEG Noise Reduction: Off
Motion Eye Care: Off
TruMotion: Off

Any help is greatly appreciated.