NO UHD

So i have a brand new OLED 65inch, the Sky now APP installed on the tv wont play the UHD content from sky, I do have the right subscription and when i use a amazon fire stick with the Now app installed it will play UHD Content, i just cant figure out why the tv installed app wont play it. The Tv will play UDH content from other apps installed on the TV so i know its capable just something between the TV and Now app wont allow UHD Content, any ideas???