grpc-dotnet: Returning null from a grpc interceptor when there is a failure status code

Why can’t return null from an interceptor there is a failure status code.

public class TestInterceptor : Interceptor
{
    public override async Task<TResponse> UnaryServerHandler<TRequest, TResponse>(TRequest request, ServerCallContext context, UnaryServerMethod<TRequest, TResponse> continuation)
    {
        if (Some Logic)
        {
            return await  continuation(request, context);
        }
        context.Status = new Status(StatusCode.Unavailable, "Some information about the issue");
        return null!;
    }
}

I don’t think I’m supposed to return a response when there is a failure status code. Or do I? When I return null with failure status code I get this error message

Grpc.Core.RpcException: Status(StatusCode="Cancelled", Detail="No message returned from method.")
at Grpc.AspNetCore.Server.Internal.CallHandlers.UnaryServerCallHandler`3.HandleCallAsyncCore(HttpContext httpContext, HttpContextServerCallContext serverCallContext)