Dove
I hope that I am not going to confuse you. First I would call a Pfaff dealer.
I have a QE 4. The owner manual leaves a lot to be desired.
For the 3.0 and 2.0 machines on page 3:7
"To engage the free-motion position, move the presser foot lift up and push the switch (A), on the underside of the lift, towards you until it snaps into place. Release the lift and it will be set in the free-motion position.
To disengage the position push the lift slightly upwards and switch (A) away from you until it snaps into place."
Let us know what you find out and if this is the answer to your problem. I wish I could be of more help.