To ensure that you are recording each input to a separate track (poly WAV file) in order to do editing in software, check the Rodecaster settings before you start recording.

Select the Gear Icon in the top left hand corner:

Once there, go to Advanced > Audio > Multitrack. Then select microSD if you are recording multitrack to microSD, your laptop or both. Select USB when you wish to record only to your computer.

When both microSD and USB are deselected as per below, the Rodecaster will record in the default Stereo format.