Welcome to the Roku Community.
We appreciate you reaching out to us regarding the flickering issue on your Onn Roku TV. We apologize for the inconvenience this has caused. We suggest trying to turn off your TV and turning it back on after 10 -15 minutes to see if the issue resolves itself.
If the issue persists, please provide a screenshot of the problem and additional information such as when the issue first started, if any changes were made to the TV's settings, and if any other devices are connected to the TV.
This will help us better understand the situation and provide an appropriate solution.