@markwkidd thanks.
Actually, it might be something that we can solve on our end on autoconfig.
Adding the following to the mapping on /opt/retropie/configs/all/retroarch-joypads solved it:
input_b_btn_label = "Cross (down)"
input_y_btn_label = "Square (left)"
input_select_btn_label = "Select"
input_start_btn_label = "Start"
input_up_btn_label = "D-Pad Up"
input_down_btn_label = "D-Pad Down"
input_left_btn_label = "D-Pad Left"
input_right_btn_label = "D-Pad Right"
input_a_btn_label = "Circle (right)"
input_x_btn_label = "Triangle (up)"
input_l_btn_label = "L1"
input_r_btn_label = "R1"
input_l2_btn_label = "L2"
input_r2_btn_label = "R2"
input_l3_btn_label = "L3"
input_r3_btn_label = "R3"
input_l_x_plus_axis_label = "Left Analog Right"
input_l_x_minus_axis_label = "Left Analog Left"
input_l_y_plus_axis_label = "Left Analog Down"
input_l_y_minus_axis_label = "Left Analog Up"
input_r_x_plus_axis_label = "Right Analog Right"
input_r_x_minus_axis_label = "Right Analog Left"
input_r_y_plus_axis_label = "Right Analog Down"
input_r_y_minus_axis_label = "Right Analog Up"
input_menu_toggle_btn_label = "Home"
There's a repository with lots of these mappings here, following @mitu 's thread (thank you!):
https://github.com/libretro/retroarch-joypad-autoconfig/tree/master/udev
So it's probably something that's RetroPie-specific for now.
Thanks both.