Automating pentagon drops sound

Hello,

I can insert Pentagon I, play and hear notes, and even automate controls (filter sync in this case). However, after I automate and play back, no sound  is heard out of that instrument track. I can see the controls changing and even play my keyboard to hear what I want to hear, but still when I play the recorded midi, I hear nothing. This is a very frustrating problem as I can automate other synths and play them back just fine, but for some reason, pentagon doesn't want to work. Any help would be appreciated. Thank you.