I got one of these because i didn’t want to pay 100 euro for a dock.
When I plug in my 2 Xbox controls both will work on it but I can’t play 2 player Gamecube games.
Is there maybe something in settings I should be doing? Specifically trying to play Mario Kart Double Dash with my son.
The only things you really get with a dock format is they usually have a display port connector, and a base-built in. The cases I use all have kickstands, so I prefer USB-C hubs myself. Also way easier to carry around in your case/bag than a dock.
In the emulators you usually have to go into the control settings and set which controller/device it sees as controller 1, and controller 2 etc.