GRPC JAVA .NET

I have a GRPC Server in .net C# . This server work with c# client grpc. I write a grpc client in Java Android . I used wireshark for check package between client and server and client seems try to conenct server but grpc server does not receive package and repsond. Server should receive and send command to client (bidirectiponal) and client should be always connected to server for receive command and also send commond (unidirectional). I need someone very export in both Java and C# .NET Framework for chek what's wrong on my code or check if it's a compatibility problem. C# Server use also interface. Pls do not make offer if you don't have required skills!