Amazon Fire TV 4K only outputting 1080p

[RoyMi6]

Just got a Hisense 55U7A but my original AFTV 4K is only outputting 1080p (see it when the details pop up when selecting the input)

When I change the display options on the AFTV between 720 50/60hz and 1080 50/60hz options they all get reported correctly but when I change to “auto (4K)” it only does 1080p 60hz.

Any ideas? It’s my first 4K device but (although I’m not 100%) think my cables are suitable (not Monster but not scabby threadbare things either)

 

[RoyMi6]

Cheers for all the tips guys.

As some have suggested I think it doesn't help my Amazon Fire TV 4K doesn't appear to run the menu in 4K, but I also found out I need to enable HDMI "enhanced more" on the input for the TV

So I'll need to run through all my testing again i.e. firing up streams and whatever.

Wish me luck!