Media Stream `start` event is not coming for deployed server[ Tried both [fly.io/ec2]

I am getting only media event in websocket.
Can anyone help me what is the issue. 
I am getting start and connected event on my local development server but not in deployed server. Because of this voice is not going through twilio 

https://www.twilio.com/docs/voice/media-streams/websocket-messages#start-message