gRPC Status Code : "Internal", Details : "Incomplete Messages" .Net 5

I am really newbie in gRpc, I am trying to add gRPC to my Rest api based services but I am getting an "Internal" error from server side.

Rpc Excepion

But When I create a new gRPC service based application as a server using VS (.net 5), with the same client, it is working.

Here my proto in server side :

syntax = "proto3";

option csharp_namespace = "GrpcServices";

package greet;

service Greeter {   rpc SayHello (HelloRequest) returns (HelloReply); }

message HelloRequest {   string name = 1; }

message HelloReply {   string message = 1; }

**The same proto file is used for client side.

This is the method in server side

services.AddGrpc() and

app.UseEndpoints(endpoints =>
            {
                endpoints.MapGrpcService<GreeterService>();

                endpoints.MapControllers();
            });

added to Startup.cs

Finally, my purpose is using Rest and gRPC in the same application in .net 5,

any help would be great, thanks