No handshake between Illico 4K Ultra-HD PVR and Samsung Crystal UHD DU7100

Here’s what’s really happening; 

your terminal and tv communicate using HDCP 2.2. Your new tv supports it but the terminal supports an older version and that’s why unplugging the cable and plugging it back in works for a few minutes because it forces a new handshake.

You can try these steps: 

1. turn off HDMI-CEC , Samsung calls it Anynet+ .. this fixes about 70% of handshake failures. 
   
   
2. limit the hdmi input to 1080p, this sometimes stabilizes the connection

Your best solution would be to switch to Helix with newer technologies