the Fv-1 pitch and octave has some definite limits on how well it track’s especially at extreme settings and when mixed full wet, if everything else is functioning properly, and there are no defects or odd substitutions with the build chances are you are bumping into the limits of the chip set. Latency acceptability is a little different for everyone. I think there is some intentional “latency” with that specific effect to get the “organ” sound. I could be off the mark on some of this but this has been my experience. YMMV