Mine is a straight rip from mkv. Looks like I’m going to have to reencode it with different audio so it doesn’t transcode. Right?
If you don’t want the audio transcoded you would need to convert to a compatible stream. I would try checking selecting Forced for direct play to be sure it doesn’t work (this should not transcode, but you may get no audio).
Note that video is not being transcoded, so the video issues are likely directly related to HDR, which so far we’ve found have to do with setup issues. It seems everything has to be just right for HDR to work.
It will probably be worthwhile to check out Roku’s guide in the link below.