I have an app that I am trying to get working on FireTV as well as phones and tablets and the first thing I noticed is that the content spills off the screen in all 4 directions, but this does not happen with my app on phones or tablets, nor does it happen with other devices (such as a Roku) hooked to the same TV. The stuff that came on FireTV all looks fine, so I'm sure there is some simple adjustment I have to make, maybe just adding some margin or padding to the outermost container if it is being used on a FireTV. I tried modifying a sample and saw stuff starting to go off the screen then too, so I have no clue what the right way to fix it is. Anyone know what the "right way" is to take care of this? If it is padding then that's fine, I just want to try to do this stuff correctly to lessen headaches down the road.
I did look at the sample but as soon as I tried to change it I started to see stuff fall off the screen and I haven't figured out what the key is yet. I put together a basic sample that demonstrates the margin problem I am having and the zip has a photo of my TV with the app on it so you can see what I am talking about. The first graphic has part of the top and side cut-off when it runs on Fire TV, but on phones and tablets it shows the whole thing. This is the same sample I used for the click issue. http://184.108.40.206:83/android.zip
For future reference, this issue is called "overscan." Different televisions may provide different amounts of overscan, where more or less of the display gets cut off on the edges. As you discovered, there is an option in the Fire TV settings to adjust the overscan. There may also be an option in your TV menus ("zoom" or "fit" or just "overscan," everyone has a different name for it). The problem of differing amounts of overscan in different TVs is why we suggest in the UX guidelines for Fire TV that you avoid placing any of your app content within 5% of any edge of the screen. That will enable your app to avoid looking like the edges are cut off. See
https://developer.amazon.com/appsandservices/solutions/devices/fire-tv/docs/design-and-user-experience-guidelines for more.