As far as it matters for this, a hypervisor is a hypervisor.
I use qemu/kvm because it’s what I’m used to on the linux side, but I don’t think it has any particular feature that makes it more safe compared to like virtualbox or vmware or anything else.
I don’t disagree, but if it’s a case where the janky file problem ONLY appears in Jellyfin but not Plex, then, well, jank or not, that’s still Jellyfin doing something weird.
No reason why Jellyfin would decide the French audio track should be played every 3rd episode, or that it should just pick a random subtitle track when Plex isn’t doing it on exactly the same files.