All Roku devices support HLS. Some handle deviations from the HLS spec better than others though. Also, newer devices unofficially support mp3 audio in videos as well as AAC, whereas older devices only support AAC in videos and mp3 in audio only. By older devices, I mean anything running firmware 3.1, and sorta brick-shaped instead of a hockey puck shape.
General issues with HLS that affect all roku players, but the older devices most strongly:
Keyframes, SPS and PPS not at beginning of segment Segments not aligned between bitrate variants Server isn't using http 1.1 Segment window smaller than 8 segments Segment size smaller than 10 seconds. Chunk list updated on CDN before the segments listed in it are available, device attempts to retrieve segment before it actually exists General Audio or Video encoding errors.
I suggest you check that major version is 3 and don't worry about minor version.
Alternatively, as the number of legacy 3.1 devices in use is declining, you may wish to simply exclude that platform from publication, let us know when you submit the channel and we can make that setting change for you.