@voljega ... issue solved .. I made 2 actions : Plug-out from RPI3 , the Mayflash adapter for my Atari 2600 Paddle (not working with Recalbox) , and switch USB order of the 2 EG STARTS USB Encoder to assign RETROPAD1 to Player1 and RETROPAD2 to Player2 ... and know HotKey works !

FM