I was just about to email support as I was convinced my pedal was borked, but I found this thread. I was just revisiting a Cmaj patch for Diatonic, with A unison and B +3rd. ( I used it for playing the second part of Bad Co Can't Get Enough Solo).
If I play C (5th str 1st fret) and E (6th open) together I get E and G# sounding. If I pluck both and then keep plucking the tope E as the C string dies away the G# drops back to G. Happens in other keys too. It seems the algorithm isn't able to distinguish the notes when two are played together. Very poor indeed.
3.0.0 beta