Apple TV4 Screen is squashed!

Set up a Wintv Dual hd stick in the back of my Shield TV. The OTA plays fine on my Shield TV yet on my Apple TV4 is squashed up into a square. Any ideas would be greatly appreciated

I have the same problem using a Wintv Dual hd stick into my PC which runs Plex Media Server. If I watch via the web client the channels have the correct aspect ratio, but if I use the Android App it seems that SD channels get squished, HD channels are fine though.

The Plex player App on the ATV4 is pretty much spot on, and passes the “Wife test”. Whereas the Shield TV is a bit too busy on it’s front end.