I followed this blog to setup manual gRPC load balancer between two EC2 instances, https://aws.amazon.com/blogs/aws/new-application-load-balancer -support-for-end-to-end-http-2-and-grpc/ but seems like it's not working. I tired every possible option ...
Using AWS Application Load Balancer and Network Load Balancer with EC2 Container Service | Nathan Peck
NET304_Deep Dive into the New Network Load Balancer
New – AWS Application Load Balancer | AWS News Blog