External MIDI Synth : Notes keep ringing when switching Patches on MS

For a start I'm a Prog Rock live performer and that demands using a massive amounts of patches per song. We're looking here at 300+/- patches for a 1.30mins gig.

Ive been using mainstage since MS1. and I've built custom patches layering external synths (ive got a korg karma and a Micro korg) and Logics instruments .

my patch changing has got to be sometimes very hectic, using one patch only for half a bar and another for another half. The thing is.. Changing patches on MS2 used to work perfectly fine. Now theres this bug that if I'm holding a chord (pressing keys not sustain pedal) that is triggering a sound on my Karma and I press my footswitch (assigned to Patch up) those notes i was holding on the karma patch would still carry on ringing! this is really annoying and inconvenient since using a panic button (assigned to my Controller) won't stop it, I have to go to my KARMA and manually press the Panic button on it , making me losing vital seconds of the tune i'm playing.

I've tried "difer patch" thing but that does not solve the problem entirely.

I've upgraded as well to the latest , 3.0.1 version of MS but that bug WASN'T FIXED!! HELP! I've got quite a few gigs coming up next month.

I'm massively dissapointed on Apple with this bug, I don't understand why youve changed this!