Often when watching 4k/HDR content on the samsung app I get random hangs with spinner showing until I ff or rewind to only have hangs again later. aTV app works fine with the same source. It is not particularly high bitrate (30mbit), it’s not a network issue.
It is transcoding from your server? Does transcode directory have lots of space?
No, direct play or direct stream. Transcode dir is on Ramdisk with ~50G and not full, tautulli shows a healthy transcode (direct stream) buffer of 1/4 the movie.
