Unable to login after started using market feed

[rajendrasp]

I have been using APIs for some time now but today I started using market feed API and after few successful attempts, it has started giving me following error at login

{"data": "{"data": {"Code": 504, "Message": "Error occurred to initialise the session"}}"}

I noticed that it is not closing the app properly when I started using feed API. I am calling un_subscribe when closing the app but it does not close the app even after calling this and gets stuck. My guess is websocket is still on and so the application is stuck and not closing. So I close VSCode and re-open it. And after few iterations like this, it started giving me the error at the login. Any help on how to resolve this?

Also, how can I make sure that websocket gets closed while closing the app?