SOLVED: Roku Express 4K: Error During Playback

[mjd]

I have a file that plays back correctly on my "Roku3" and "Roku Premier 4k" but when trying to play on a "Roku Express 4K" I get an immediate "error during playback" message on the roku. Transcoding in general works on the server and most of the videos play correctly on the Roku Express, only a small percentage seem to give this error (I'm not sure what to look for in a commonality. I'm open to suggestions.)

I don't know the first thing about media formats and codecs so I don't know how to begin troubleshooting this other than giving all the relevant info. Any advice on what to look for or what to try next would be appreciated.

Roku Express 4K app version 1.6.6

Server: jellyfin
Version: 10.8.10
Operating System: Linux
Architecture: X64

Video
Title: 1080p HEVC SDR
Codec: HEVC
Profile: Main 10
Level: 120
Resolution: 1920x1080
Aspect ratio: 16:9
Interlaced: No
Framerate: 23.976025
Bitrate: 6159 kbps
Bit depth: 10 bit
Video range: SDR
Video range type: SDR
Pixel format: yuv420p10le
Ref frames: 1

Audio
Title: English - Dolby Digital - Stereo
Language: eng
Codec: AC3
Layout: stereo
Channels: 2 ch
Bitrate: 192 kbps
Sample rate: 48000 Hz
Default: No
Forced: No
External: No

Code:

[2023-07-24 10:11:41.530 -04:00] [INF] User policy for "user". EnablePlaybackRemuxing: True EnableVideoPlaybackTranscoding: True EnableAudioPlaybackTranscoding: True
[2023-07-24 10:11:41.537 -04:00] [INF]
StreamBuilder.BuildVideoItem(
    Profile="Anonymous Profile",
    Path="/mnt/video/TV Shows/redacted.mkv",
    AudioStreamIndex=1,
    SubtitleStreamIndex=-1
) => (
    PlayMethod=Transcode,
    TranscodeReason=AudioCodecNotSupported
)
"media:/videos/22ef73c5-f296-4ee8-cc96-0a25eb41d31c/master.m3u8?MediaSourceId=22ef73c5f2964ee8cc960a25eb41d31c&VideoCodec=hevc,h264,hevc&AudioCodec=aac&AudioStreamIndex=1&VideoBitrate=40000000&AudioBitrate=384000&MaxFramerate=23.976025&api_key=<token>&SubtitleMethod=Encode&TranscodingMaxAudioChannels=2&RequireAvc=false&Tag=89cdd9ffb1c22f64c4122b1541221b90&SegmentContainer=ts&MinSegments=1&BreakOnNonKeyFrames=True&hevc-level=120&hevc-videobitdepth=10&hevc-profile=main10&hevc-rangetype=SDR,HDR10,HLG&TranscodeReasons=AudioCodecNotSupported"
[2023-07-24 10:11:42.275 -04:00] [INF] Playback stopped reported by app "Jellyfin Roku" "1.6.6" playing "redacted". Stopped at "0" ms