I just bought an Apple TV 4K 64Gb, and I tried Infuse player.
I tried to play LG Chess HDR UHD 4K Demo, but it doesn’t play correctly. It takes 5-6 seconds to start playing and without the audio. (when I select the file, on the information screen, the audio doesn’t detected at all in the description.)
I tried to play the same file with VLC, and it works without any issue.
Here the file that I’m using: http://4kmedia.org/lg-chess-hdr-demo/
You may find there the link to download the file and try.