I’m also looking for a solution to using Home Assistant on my Android TV’s and never had any luck using the regular Android APK version when I tried it on my Bravia due not be able to navigate. Got several TV’s I’d really like to use for dashboards and casting isn’t really ideal for what I’m looking for.
I have a few integrated Fire TVs I use as dashboards, displaying weather/status sensors (no interaction). I ran into similar issues where I couldn’t find a route to display dashboards other than using the built-in Silk browser. Typing in a Home Assistant URL with a TV remote isn’t too much fun!. For a more permanent and user friendly solution, I opted to build an Android app with a simple WebView pointing to a predetermined Lovelace dashboard. Now, I can just open the app and it performs an autologin and loads the dashboard.
Can you share more information please?