Direct play on Infuse over the internet

I’m trying to let my mother stream my 4K HDR content via Jellyfin over the internet. Currently this content is streamed over SMB inside a WireGuard VPN tunnel and played on her Apple TV 4K. It’s working okay but I would prefer to use Jellyfin.

I’ve disabled transcoding for her user and added my Jellyfin server is added in her Infuse app. However I get this error message when trying to play some content:
An error occured
An error occured loading this content.

I know that Infuse can direct play the content so the problem must be with the Jellyfin config/server.

Is there a setting that I have to change to enable direct play over the internet?

There shouldn’t be anything needed to make that happen. It should just work to be honest.

Did disabling transcoding from the other thread make any difference?