Bs Recorder Gold 8 problems

I’m using Bs Recorder Gold 8, direct-cutting audio from a digital multi-track into the line in jack on my computer via a Y-connecter. If I plug in the jack all the way I only get one channel to record. If I pull it out partway, I get both channels but no stereo separation. I’m assuming the program is capable of recording in stereo. Any ideas? Thanks.