Mod wheel modulation sounding when when wheel is off

[henryburnett]

Hi, just getting acquainted with my new Mopho X4 and I've come across something puzzling.

I'm trying to assign the mod wheel to control vibrato via LFO 1.

I set LFO1 to modulate Osc1&2 pitch and set the amount to 0.

Then I head to 'modulators', choose ModWhl and dial in the amount, say 30.

The mod wheel now adds the pitch modulation - HOWEVER - a small amount of pitch mod is still present when the wheel is fully down. The larger the amount I set for the wheel to control the LFO amount, the more pronounced it is even when the wheel is off. It's like the wheel isn't properly hitting zero.

I've calibrated the wheels but no change.

Any thoughts?

Thanks,
Henry