bouncing midi controller values to external VSTi

I have X1 on a master PC sending midi via MolCP3 to several VSTi on a slave PC. Audio returns via VEPro. Everything is A-OK on playback. I can see notes and controller values arriving in the VSTi, and hear the expected audio changes back at the master PC.
 
When I try real-time bounce (fast bounce is unchecked), I no longer see cc values arriving at the VSTi, nor do I hear the expected audio changes that would result.
 
Is there some other process requirement to make this work? I remember now this gave me the same problem in 853.