problem installing 4th button on recalbox rgb jamma

[sebidouille]

Hello all,

I have a two-player arcade cabinet in which I installed a Raspberry Pi 4 with a Recalbox RGB Jamma. The Recalbox version is v9.2.3. I did not change anything for the BIOS and I installed two ROMSETs: FBNEO and MAMES 2023.

I changed the joysticks and buttons. There were initially 3 buttons per player, I installed a 4th for each player. I tried to connect the 4th button in Jamma or CPS1, but in both cases, I have the impression that they are not detected. I changed the settings in NeoGeo to enable the 4th button, although I am not sure if it is necessary. I entered RetroArch, but I can't find anything to enable. I searched in Recalbox Manager, but I couldn't find anything.

Can someone guide me to understand where my problem is?
Is there a solution to test this 4th button to understand if I made a connection error?
Or did I miss a setting?

Thanks in advance for your help.