It’s doing the same thing with mine but it won’t change back until I leave the video or game!
Thanks for your first post in the Roku Community!
We would be more than happy to look further into this issue but will need more details. Can you please provide us with the following information:
As a first step, try taking a look here for more tips about troubleshooting that might help the issue: How to improve contrast using local dimming on your Roku TV™ | Official Roku Support
Please keep us posted and we'll continue assisting you from there.Best regards,Mary