C-1 note triggered on Stop or Start in Transport

I have an issue with East-West Opus and CB12 Pro.
When I use Play or Stop on transport (via midi controller or onscreen in CB), I triggers a note and I have to do MIDI>Reset.
It always triggers C-1. I wondered why I always heard only the basses sound, it’s because the basses are typically the only thing in my project that goes that low.
When I have an instance of Opus with a full set of instruments, it will trigger that C-1 bass note regardless of what MIDI channel is set for the basses.
Could this be an OPUS issue, or something else?