I’ve made JellyFin and a few other services available from the semi-static IP that I get from my 5G antenna so that where ever I am I can stream my library from jellyfin.mydomain.com. Video and audio in general works fine everywhere, but when streaming on my mobile, some videos are missing the voice track. I suspect this has to do with voice being encoded in a 5.1 format on some files. Is there a way to force stereo on my mobile?
Almost always this is a player issue as mentioned. I’ve had similar issues with some files where audio just doesn’t work on one player but works fine for another. Same with subtitles. Set to an external player like VLC and see if that fixes it. (For what it’s worth, I mostly access Jellyfin from my Chromecast and I have it set to prompt me for a player each time I start watching something, one of them always works but for my files it isn’t consistent which)