GRPC call returns 'PROTOCOL_ERROR (0X1)' for a .NET application on EKS

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My .NET application is deployed to an EKS cluster, which has an ingress defined with the following relevant annotations alb ELBSecurityPolicy-TLS-1-2-2017-01 '[{"HTTP":80}, {"HTTPS":443}]' internet-facing ip '{"Type": "redirect", "RedirectConfig": { "Protocol": "HTTPS", "Port": "443", "StatusCode": "HTTP_301"}}' "/swagger/v1/swagger.json" HTTP2

My app deploys fine on the cluster with all healthchecks passing and pods in running state. However, when I query the ingress endpoint with a GRPC request, I get an error as shown below in brief

Unhandled exception: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> Grpc.Core.RpcException: Status(StatusCode="Unavailable", Detail="Error starting gRPC call. HttpRequestException: An error occurred while sending the request. IOException: The request was aborted. Http2ConnectionException: The HTTP/2 server sent invalid data on the connection. HTTP/2 error code 'PROTOCOL_ERROR' (0x1).", DebugException="System.Net.Http.HttpRequestException: An error occurred while sending the request.

I am sure there is not an issue with the request in question, because when I do a port-forward on one of the ports and hit the localhost:5000 endpoint, I am getting the desired result.
I checked the loadbalancer and target groups in AWS console and they're in healthy state. However the monitoring dashboard show adds to the ELB 4xx count every time I access the endpoint. I am sure there is an issue at the ingress level but I am unable to figure out what exactly.
Not sure what I am missing here or if there is anything wrong with my setup. But since the port-forward works as expected, this has got to be some issue with the LoadBalancer.
For reference, I have tried changing the backend-protocol-version to GRPC which does not help


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