Game list not matching choice

I've been trying to organize my Naomi and Atomiswave, and getting them working with Demul.

I had everything working externally out of GameEX but when I tried to make sure it work in GameEX my selection list doesn't match my choice. But only on some, not all. So if I choice 18 Wheeler I get Alien something, but Marvel vs Capcon, I get Marvel vs Capcon. It's weird, any ideas?