I am using unity 2019.3 and installed latest azure speech SDKas far as I know. I also subscribed to pay as you go plan. Here is the error generated in unity:
CANCELED:
Reason=[Error]
ErrorDetails=[Connection was closed by the remote host. Error code: 1011. Error details: Internal server error. USP state: 3. Received audio size: 0bytes.]
Did you update the subscription info?