Dave Smith Instruments SYNTHESIZERS

First timer here... greetings to everyone :)

Does some of you have experience sequencing a PEK from an MPC? I have this problem: Some voices on the PEK turn on with a very low pitch whenever I touch a knob while playing MIDI from the MPC.

If that wasn't clear enough, this would be how to replicate it:

1.- Press record+play on MPC and play something on the PEK. (PEK has local control off).

2.- Loop plays back well on PEK.. press stop on MPC.

3.- hit play on MPC, all good, PEK behaves well.

4.- while playing, turn PEK's filter cutoff knob...and...

5.- One of the PEK voices turns on with a very low pitch and it never turns off, until...

6.- Press STOP twice on MPC and voice turns off.

I've been playing with the local control and the soft thru midi option on the MPC, but I can't get to find a setting that allows me to work without changing this settings all the time.

My moog voyager (rack) and my waldorf microwave xt (also rack) never complain like the PEK.

Thanks!