Why won't node gRPC server side streaming end after cancelling from grpc-web client?

Question

I am trying to stream data to browser client using gRPC Node library. I am using grpc-js for server and grpc-web for browser client using vue-2. I am using @grpc-web/proxy as a middleware. I could successfully perform server side streaming using above configuration. I now want my client to cancel the streaming when further data is not required.

I tried using call.cancel() as mentioned in the gRPC documentation and can see that the client stops processing the data but this event is not caught by the server (ideally should be caught using call.on("CANCELLED") event.) Has anyone tried doing this? I am not sure if the issue is with proxy or grpc-web library.

NOTE: I've used the same server code, streamed data on postman and was able to cancel the stream on server side.