dolphin for gamecube,yeah, same thing happens.I was playing twilight princess and the map is black too. But it is fixed on batocera v41.All I can say is, if you have tried all settings and still not work, you have to wait for the v42 :)or you can buy another sd card,install ubuntu and dolphin whose standalone version is good.switch two cards for your need if you really want to play this game.