FBNeo subsystems menu in RetroArch non-functional on PS Vita (and possibly others)

[kwyxz]

On Playstation Vita, the FBNeo subsystems menu is non-functional.

To reproduce :

• load the FB Neo core
• select a subsystem
• load anything that isn't arcade
• start

Retroarch will go back to the menu and the logs show No content, starting dummy core

Even after creating a playlist to specify the subsystem, the ROM seems to load but then the core doesn't run properly. Log says [libretro INFO] Driver md_sonic was successfully started : game's full name is Sonic the Hedgehog (Euro, USA) but immediately goes back to the RetroArch menu.

Here's the playlist I created, for info. Maybe I bungled it?

$ cat Sega\ -\ Mega\ Drive\ -\ Genesis.lpl 
{
  "version": "1.2",
  "default_core_path": "",
  "default_core_name": "",
  "label_display_mode": 0,
  "right_thumbnail_mode": 0,
  "left_thumbnail_mode": 0,
  "items": [
    {
      "path": "ux0:/homebrew/roms/sonic.zip",
      "label": "",
      "core_path": "app0:fbneo_libretro.self",
      "core_name": "Arcade (FinalBurn Neo)",
      "crc32": "",
      "db_name": "",
      "subsystem_ident": "md",
      "subsystem_name": "Sega Megadrive",
      "subsystem_roms": [
        "ux0:/homebrew/roms/sonic.zip"
      ]
    }
  ]
}

Logs attached. retroarch2019_11_1616_15_08.log

[kwyxz]

According to @barbudreadmon this is a RetroArch bug and the FBNeo core works properly. NeoCD games are loading through Load Content because they are indeed in a folder called neocd but won't load through the subsystems menu. Other systems would load through Load Content with folders renamed.