We couldn't really reproduce the problem that you're describing.  The only case where we were hearing dramatic changes was if the Depth knob was turned all the way up.  If what you're hearing isn't related to that, you may want to restore your H9s system settings, as this might be related to that.  You restore the system settings by turning your H9 off and then turning it on again with the right footswitch and the HotKnob switch pressed (the knob in the upper left hand corner of the H9).  This was wipe out any changes you've made to your H9s system settings but won't affect your presets.