Sony displays have advanced video processing features meant to enhance the picture. Unfortunately, some of these settings negatively interfere with the picture, causing the result to be worse than the original signal.
Over-processing will present in one of these ways:
As menus are slightly different depending on the model and firmware version, please search for the closest menu approximation:
Essentially: disable anything that claims to make the picture "better".
If these steps do not resolve the issue, please contact Support for further troubleshooting.