HDR AV1 in MKV direct play does not work in LG C1

[msimic]

I think AV1 in MKV is not supported by the LG C1, the player tries to do Direct play and never starts.
What you get is an endless spinning circle.
For AV1 HDR I'm not sure if it supports it at all.
The player should probably request transcoding or there is some other issue when the Direct play tries to start.
The file works fine on my desktop in Edge, and doesn't do a transcode.
But the TV won't budge.

This is the MediaInfo of the file I tried:

Video
Title: 4K AV1 HDR
Codec: AV1
AVC: No
Profile: Main
Level: 12
Resolution: 3840x1604
Aspect ratio: 2.40:1
Anamorphic: No
Interlaced: No
Framerate: 23.976025
Bitrate: 13935 kbps
Bit depth: 10 bit
Video range: HDR
Video range type: HDR10
Color space: bt2020nc
Color transfer: smpte2084
Color primaries: bt2020
Pixel format: yuv420p10le
Ref frames: 1

If the problem might be the audio this is the info:

Audio
Title: English - OPUS - 7.1 - Default
Language: eng
Codec: OPUS
AVC: No
Layout: 7.1
Channels: 8 ch
Bitrate: 414 kbps
Sample rate: 48000 Hz
Default: Yes
Forced: No
External: No

If I force PGS subtitles the file starts on the TV and uses transcoding (but no HDR in this case).