SOLVED: Successful transcodes in browser, but not on other devices

[abaxi]

Can you share the full media info for this video as shown by the Jellyfin UI?

The video stream has info:

Code:

Video
Title: 1080p AV1 SDR
Codec: AV1
Profile: Main
Level: 8
Resolution: 1920x802
Aspect ratio: 2.40:1
Interlaced: No
Framerate: 23.976025
Bitrate: 1679 kbps
Bit depth: 10 bit
Video range: SDR
Video range type: SDR
Color space: bt709
Color transfer: bt709
Color primaries: bt709
Pixel format: yuv420p10le
Ref frames: 1

The audio stream has info:

Code:

Audio
Title: OPUS - 5.1
Codec: OPUS
Layout: 5.1
Channels: 6 ch
Bitrate: 228 kbps
Sample rate: 48000 Hz
Default: No
Forced: No
External: No

---

I'm not exactly sure why it would transcode when streaming to the browser but not elsewhere, as the Chromecast 4K and my desktop clients do not support AV1.

because the source video is already compatible with the client, PlayMethod=DirectPlay
and because the android-tv app does not have force transcoding settings
that means the client does not request a transcode

transcoding settings on the server only tell the server what it is capable of doing IF THE CLIENT REQUESTS IT

the server cannot force clients to take a transcoded version

What does "compatible" mean here? Why would the client request a direct stream for a codec that it's not able to decode?