I have described it here: Kemper Transpose vs Digitech the Drop problem
There was no solution so far. I just keep using the Drop pedal.
I have not used the transpose function for a while. When I engage it I continue to hear an "artifact" of the tonic note. It is not vibration or the string. It is clearly in the headphones and of course with a 1/2 step detune sounds horrible. I see this has been discussed already, but I can not find a solution. The "turn it up until you can't hear it" does not sound like the correct solution. Any other experiences with this?