To do this you need to load the relevant MP bank, and then open 'Multi Pad Creator' (press CREATOR > MULTI PAD CREATOR).!
Once open, at the bottom of the screen you will see options for 'Repeat' and 'Chord Match' for each of the four pads in the bank.
It is the 'Chord Match' setting that you need to set to 'Off' to prevent the pads from following chords.
Set as appropriate for each MP, then save the bank to make your changes permanent.
Note that MPs using non drum voices will still be transposed if the keyboard is transposed even with Chord match turned off, but will not follow chords played.
Regards
Ian