Left and Right Channels overlapping in WAVE view

I need to edit the left and right channels separately within the wave view. I need this to be quick as we still do a live radio show. It has been fine for weeks and TODAY, the left and right channels show as overlapping in wave view and we don't know why. 

How do I get this to be separate again? I don't believe I did anything except restart my computer.

The file IS stereo not mono. 

thank you!