Check your TV screen settings, too. It could be that your settings are affecting the viewed image size
The outer margin at 90% is called the Action Safe margin. In the days of analog tv, anything outside that margin was subject to being lost due to overscanning or being covered by the bezel. Anything important needed to be within that margin. The inner margin at 80% is called the Title Safe margin. Text needed to be placed within that margin, not because it was subject to being cropped off, but because the video quality near the edges of the CRT was originally so bad that it difficult to read anything placed there.
Modern digital TVs don't have the same problems as those analog sets, but it's still recommended to follow the safe margin guidelines. First, because digital tv settings can affect the display size effectively cropping off part of the image. And, second, if ever viewed on a mobile device, the screen aspect ratio may not match and viewing full screen could also crop off part of the image.
[ Post made via Mobile Device ]