Chromatic notes filled in between MG2 default notes

I have had MG2 since June 2018. It is marvellous apart from one fundamental problem.

I can not get MG2 to play notes input from a guitar without it inserting all chromatic notes in between. This problem is even apparent using the MG2 stand alone test piano. It can also be seen on the virtual keyboard when just playing on one string. Eg with a guitar plugged in hammer on and off at the 2nd fret of the low E string. The virtual piano plays E, F, F#, not just E and F#. There is no bending involved. These chromatic notes also show up when recording MG2 as a MIDI instrument in Logic Pro X.

In the MG2 MIDI Monitor I have noticed that ‘Pitch Wheel 8192Channel1’ is displayed before every ‘Note on’ event. Is that relevant?