Why is the screen on my Smart TV flickering?

Make sure the cables are connected properly
Check that all cables are securely connected to both the TV and device.
Check power and last configuration changes
Identify any recent power or configuration changes that may have caused the flickering.
Check any supported proprietary tweaks
Look up for any existing proprietary tweaks or settings, and if the problem persists try toggling the settings, or reset them all to their default.
Check external peripherals or interferences
Reboot external device(s) such as consoles, sound bars and any additional peripherals, as other devices or interferences may be the cause of the issue.