Just to add a +1 seeing this issue.
I’m using a flirc firetv edition with a harmony remote, but the enter/ok button does not work in some specific applications.
its working fine within the main device menus and most other apps.
so either the issue is with the firetv itself, or some apps are not responding to the same remote codes.
@jason did you ever get to the bottom of this with your previous investigation?