It's a machine, I was trying to do shots on D bass in a 12 bar blues in D, but it kept playing different notes. After trying for hours I thought it was a bug until seeing your post, then the penny dropped, it was shot-ing on D but hitting random chord tones so I had to enter Bb/D to make it work.

Now I want to enter a 4 bar drum solo & can't find a drumkit in the soloists list, PG customer support maintains that drummers don't play solo's. cool