Roku setup

[cellis4766]

I have a new Roku Ultra, but can't seem to get the settings correct. Every few minutes the screen goes black for 10 - 15 seconds and when it comes back on, it says "Dolby Vision" in the upper right corner of the screen - I think its trying to change the display to a different setting. After switching to the black screen and back several times, the Roku disconnects and I either need to unplug the HDMI and plug it back in, or switch the ports on the Philips Hue Sync Box several times to get the Roku to display again. I've changed the video and display settings in the Roku box, and the television but it seems to continue no matter how I have it set up.  

My current setup (in order of connection) is:

Roku Ultra
Philips Hue Sync Box
Vizio Elevate Soundbar
LG 65C2 Television

Prior to this, I had a Roku Streaming Stick, which worked with no problems, and other inputs into the Play box also have no issues, so I'm pretty sure its the Roku Ultra. Anyone have any suggestions? It's currently unwatchable and kinda frustrating that it's not working out of the box.

[AvsGunnar]

@cellis4766 

Try disabling the Auto Refresh Rate if you have it enabled. (this should stop the screen flash).

Settings/System/Advanced System Settings/Auto-Adjust Display Refresh Rate/ [Off ]

May also want to manually set your Display Type if using Automatic.

Settings/Display Type/ [manually set your preferred type ]