Transcode issues with Jellyfin For Kodi

[mrtachyon]

Hey, I've got a Jellyfin server with a Intel Arc GPU for transcoding and it works perfectly fine with other clients (e.g web, android, android tv) but I'm having issues with the Jellyfin for Kodi client. It's not specific to a device, I've tried it on a Nvidia shield, google tv streamer 4k and coreelec and all have the same problem with Jellyfin for Kodi.

If you direct play the file then no problem, plays perfectly. But if you transcode the file for whatever reason (e.g bitrate) then it won't play - it just hangs on loading. I've narrowed it down to the "Enable external subtitles" option - if you turn this off then it plays. However, with it enabled it won't play.

Kodi logs:

https://pastebin.com/raw/xWXyMxa3

Jellyfin logs:

https://pastebin.com/raw/L7EfA7X1

From the logs it looks like it's trying to fetch some subtitles from the Jellyfin server. I'm not sure why as the file on Jellyfin doesn't have any default subtitles set. Also I'm not sure why the server appears to be trying to extract all the subtitles from the file, as you can see this takes a while as the file is big and has many different subtitles. Only the Jellyfin for Kodi client exhibits this behaviour. 

Anyone any idea what is going off here?

Thanks!