Unplug the sustain pedal after turning the instrument off then turn it back on and leave the pedal unplugged.

Now do all of your tests to see what notes/voices sustain or not. 

Just because a note/voice is 'sustaining' doesn't mean it is because of the sustain pedal. There are ADSR envelopes programmed for the voices - AttackDecaySustainRelease - the S is for 'sustain'. If the sustain value is high it will cause a note to sustain and that has nothing to do with the pedal.

Once you've done the above tests you will know which voices/notes are sustaining even without the pedal being involved. Then if you don't want them sustaining you will have to modify their ADSR envelopes to reduce the S (sustain) value for their envelopes. 

See p.26 for the [F4] EG (Envelope Generator) section of the Moxf reference manual.

In this section, set the offset value for the Amplitude EG and Filter EG of all Elements that make up the Voice.

AEG (Amplitude EG)

ATK (Attack Time)
Determines how quickly the sound reaches its maximum level after a key is pressed.

DCY (Decay Time)
Determines how fast the volume falls from maximum attack level to the sustain level.

SUS (Sustain Level)
Determines the sustain level at which the volume will continue while a note is held, after the initial attack and
decay.

REL (Release Time)
Determines how quickly the sound decays to silence after the key is released.
Settings: -64 – +0 – +63

NOTE When a Drum Voice is selected, the Sustain Level and Release Time are not available. “---” appears at each of the
corresponding columns and these parameters cannot be edited.

 

Just as a baseline, check that the sustain pedal configuration matches your pedal.

1) Press the [UTILITY] button

2) Press [F4] button.  Under utility mode (not shown above), the F4 button will be labeled as "CTL ASN"

3) Press the [SF2] button.

4) Change the sustain pedal setting to "FC4/5" (which means an FC4 or FC5 pedal) if not already set to this.

I think you will find that the default after a factory reset is FC3 (Half On) which isn't a complete match for your pedal, the FC4.

Not that this will fix everything - but it is good to have the setting match the pedal you are using.

5) Press the [STORE] button to save the changes you made to the utility options.  This tip was gathered from here:

https://www.youtube.com/watch?v=bdBQX8Lu4n0

The above video has some other various general things you may or may not want to see.  At least it shows someone else going through and making utility mode changes on the instrument itself so you get a sense of how navigating the menus works.