Alesis Multitrack...splitting tracks in GB?

I'm using a Alesis Multimix 12 with Garageband. I'm trying to give each input its own track so I can mix them later. However its not letting me split them up. Then input only shows Channel 1 + 2 stereo...or Channel 1 mono Channel 2 mono.

I've set my preferences to use the Multimix as its input but still having problems. Any recommendations? Do I need a driver?

I've used other interfaces in Garageband and they just automatically list each input line that the interface provides.

Check for a driver. Believe it or not, some hardware needs it. My MOTU 828MK II wouldn't work until I installed the software.

If that doesn't work, I'm not too sure as I've never really used GB.