@Substring because controls are mapped differently that i map inside recalbox, It Hurts messed up, when the 2 controllers are plugged.
If i plug only 1 controller It works like It should.
So when i map the controllers over retroarch, when i save config and load this config after, i lose the core, It have no core loaded, so i have to exit retroarch and maps on recalbox are lost also. It's very strange indeed.
In short, when i have only 1 controller plugged i got my mappings saved in recalbox and retroarch ok...

Oh, i used the core remap indeed, because some buttons in my controllers was opening retroarch hotkeys, so i mapped tem default (using Space on keyboard)

@Substring i dont have It now... This is his board that im using:

Now i cant enter in retroarch configuration to map the controllers, even using a keyboard. F1 does not work to open retroarch menu anymore.
Any tips?

I found this also...is there anything i could use here?

https://github.com/libretro/retroarch-joypad-autoconfig/blob/master/udev/DragonRise_Inc._Generic___USB__Joystick.cfg

Hj, i just built my home Arcade, for 2 players...
I'm having annoying troubles with recalbox when the Second controller is connected. It's a dragonrise generic ps3 USB controller board that im using for both players.
When i use only player 1 the mapping Works ok, i can map in retroarch and when im back to recalbox menu my mapped controller still works Like It should.
If i connect the Second controller, i map It but everytime i enter retroarch or come back to recalbox menu i have to map It again and again...
If i turn It off i have to remap everytime again too.
Is there any way to solve It? It's very annoying and i tried everything inside system to solve It (i dont understand nothing of Linux)
Please, help me solve it