Menu audio is fine, but no emulators have any sound at all once you start a game. This only affects games on external drives. When I switch back to internal storage all the preinstalled games and their audio work fine. I've reinstalled Recalbox, switch audio outputs and everything to no avail. No idea what's going on.
edit: Uncommenting and forcing it to HDMI does nothing, still routed through the headphone jack.