"not compatible with Android TV boxes" is a bit of a misnomer, used by Technical Support staff at companies where they're looking for the easiest way to dump you quickly. Likely a company policy rather than individual lazy trouble shooters!
Android TV boxes are for the most part very similar to an Android tablet or phone, but without a touchscreen and adding HDMI and ethernet ports.
The tech support staff haven't used an Android set top box before? Trouble shoot, research and fix. You don't need to advertise that you officially support TV boxes, but if you're presented with an issue using your company's software, better to investigate, apply logic, fix and post the knowledge somewhere online for others to find.
[/end rant]