Arcade virtual system only shows FBNeo

[jonas]

In my RB setup, I have two Libretto MAME cores and AdvanceMAME, with the respective ROMs organised as subfolders. Additionally, I also have FBNeo and some NAOMI and Atomiswave ROMs. Everything working perfectly.
However, if I enable the Arcade virtual system, only the FBNeo ROMs are shown.
What am I doing wrong?
PS: Just updated to 7.1.1

[Zing]

@jonas I really don't know what it could be, but, I haven't seen any more reports about it, so it's something very specific.
You can test on another SD card (or USB stick, you didn’t say your hardware), a clean installation of the latest version of Recalbox, and copying only the ROMs of MAME, Fbneo and Neogeo (for example), without using subfolders and, another test using subfolders?

[jonas]

@Zing I'm using a RPi4 booting from a SD card, ROMs and other system stuff stored in a 32 GB USB stick, fresh install of RB 7.1.1.
When using a MAME folder without any subfolders, the Arcade virtual system shows these ROMs as expected, together with FBNeo (and NEO-GEO, if enabled) so this problem looks like an unforeseen consequence of using subfolders... There is an option to display subfoder contents when in the Arcade menu, but it didn't help.
Nevermind about the Naomi ROMs, the documentation only mentions MAME and FB in the Arcade virtual system, so it probably won't apply to other cores/emulators.