@Substring
I give today a new try to my Gasia PS3 wireless controller (dmesg) together with my 2 dragonrise controllers on USB. Configuration, pairing everything ok.
So, I configurated the gasia PS3 (device2) on P1, moved dragonrise (device 0) to P3.
In emulation menu from recalbox everything working fine, means all 3 players joystick and buttons worked as configurated in the recalbox controller menu.
But after switching to retroarch, things mess up. It seems I am not the only one with the issues
https://forum.recalbox.com/topic/8090/arcade-usb-controllers-2-players-setup-retroarch
In retroarch, the gasia controller is not reacting anymore, but the dragonrise (device 0) is partly working, even now configurated to P3.
Partly means, no Hotkey button, Button B mapped to Button L1 ??? and so on.
When I remove the gasia from the configuration and put again the dragonrise to P1, also retroarch is working fine again.
So, for the moment no chance to use the gasia controller.