Difficulty integrating Amazon FireTV into HA

I’m trying to add my Amazon 43" FireTV into HA but am not having any luck.

I’ve followed the Android TV integration instructions, turned on ADB debugging on the TV, set up an ADB server, but immediately get a ‘connection refused’ error. I’ve verified the port (5037) is open in the firewall, etc. Anyone have any suggestions? I tried the preferred built-in adb method but that mentioned it might not work with newer TVs (it didn’t) but the ADB server is not working either.

Thanks,
Jim