Most often, the problem with displaying the content (pictures appears cropped, etc.) arises from the calibration of the screen relative to the Apple TV.

Depending on your model, check which video display settings are enabled. If in the Kitcast you use the content with a 16:9 aspect ratio, then in the settings of your screen the aspect ratio should be the same.

In order to make sure that the screen settings and Apple TV are the same – from the Apple TV main menu go to the Settings > Video and Audio > Calibrate > Zoom and Overscan, and check that the Minimum and Full Screen areas are shown as in the screenshot below.

If that picture is cut – try changing you screen's displaying preferences.
​
Thank you for using Kitcast!