Serverless framework api gateway web sockets authorization bug

I am trying to use web sockets with serverless framework, but they have a bug. https://github.com/serverless/serverless/issues/6161 if you know the fix please help out.

I have tried to work around with a lambda authorizer that calls cognito, but I don t know what the custom authorizer handler should return to API gateway. If I just return the response from cognito it breaks with 500 error.

Thanks in advance