Appstore AppleTV

Just to clarify, if you have an older Apple TV then it would not have an app store and cannot run apps. If you are using an HD (4th gen) or 4K (5th gen) model and are having issues with apps you've downloaded then you would need to contact the developer. Identify your Apple TV model - Apple Support

Then you would need to contact the developer and inform exactly of the issue, also make sure you see if it persists after a reinstall.

If the developer has adamantly refused to acknowledge then you can contact Apple