Edit: There were two issues popping up in my GDF CX VA- First, it was dropping calls to human escalation + I was seeing a no-handler error event in my logs after switching the default voice
I initially thought that a no handler for event was triggering along with the voice failure but it seems to be unrelated. Cloud logging didn't provide any extra insight besides a confirmation of the loaded voice in the service when the failure occurred.
This seems to occur far more frequently when a non-Wavenet voice synthesis agent is chosen on a phone gateway.