I had a similar issue. The problem was rectified by displaying the desktop on the Samsung display, ensure the input is in the HDMI/DVI port (typically HDMI1), ensuring that this port is labeled as a PC input (press “Inputs” button on remote, highlight the input, pres down, change input type, and set to PC). Next go to the control panel under “Display>Advanced Settings” and verify that the resolution for the 4k TV is set to the correct 3840×2160 resolution (many times control panel will incorrectly have 4096×2160 the “Recommended” resoution for a 4k TV, ignore this and set to 3840×2160).
From there you need to press the menu button on the remote and navigate to the “UHD Color” setting on your TV on the input the computer is plugged into. This setting needs to be cycled off, then back on for that input. Doing this requires the TV to restart each time.
Once you cycle the “UHD Color” option back on for that input the display should now show the correct resolution on the TV’s info button display (3840×2160 / 60p). The display should also now correctly be displaying full 4:4:4 chroma subsampling as the CAC-1070 and CAC-1170 are meant to be able to do.
Keep in mind, after cycling the the UHD Color option off then back on, the display may still not be detecting the resolution correctly (and will be putting out 4:2:2 chroma subsampling). If this is the case you will need to cycle the UHD Color option off and onn again, possibly several times until you get the desired result.
Also important to note that once you turn the TV off then go back and turn it on later the TV will have reverted to it’s previous state and you will have to jump through the “UHD Color” of-on cycling hoop again to get back to your desired result.
I am unaware of any way to make the computer/adapter/display remember the correct state after the TV is turned off.
Hope this helps, best of luck.