Rasa Upgrade 2.x to 3.x (Webchat not responding - Waiting for the Server)

Problem statement: We are trying to upgrade Rasa Open source from 2.x to 3.x. We upgraded other packages like Sanic to suite to Rasa 3.2.1. We are using socketio(5.6.0). Issue: In local, model is giving proper response after upgrade. But when we integrate with webchat(UI), chatbot is not responding.(It is showing waiting for the server and not able to type). When we check logs, we are seeing connecting to socket endpoint and getting disconnected immediately.

Softwares used: Rasa - 3.2.1 Sanic - 21.12.1 Socketio - 5.6.0

In the UI side, we have socketio (2.x) is there,I downgraded socketio and engineio to suite to UI side, but still chatbot is not working. Will upgrading UI socketio to 3.x or 4.x solves the problem? or Are we missing something in the code/packages upgrade?

If this information is not sufficient , Please let me know. We are not supposed to share logs, but i can explain in an elaborate way.

Facing a similar problem, still looking for solutions, anyone!?!