4K video is buffering after a minute, regardless of bitrate/no transcoding

Plex Players Gaming Consoles
1

I have two copies of the same movie. The 1080p version, which is 25gb AVC video, plays flawlessly on the Xbox One app. Direct play.

The second is 15gb. It’s the same movie, but it’s 4k and x265, 10-bit HDR. The movie will play fine for a minute, then start buffering. The image will go black with the buffering icon staying on screen. Nothing will ever progress pass this point.

According to the app, the video is being played directly, with only the audio being transcoded (the audio is DTS-HD MA). Obviously the issue isn’t a bandwidth issue with my network considering the larger file plays fine. Does anyone have any idea what could be causing this issue? Would transcoding the audio really result in this problem?

2

Try H264, mp4 encoding. Many have posted this resolves the problem. I have issues with H265.

3

@himwithnoname said:
Try H264, mp4 encoding. Many have posted this resolves the problem. I have issues with H265.

I didn’t think Plex for Xbox doesn’t support H264 4k videos, just H265?