Exception when adding new method in a working Service using gRPC-Web and protobuf-net

I am getting the following exception:

Microsoft.AspNetCore.Components.WebAssembly.Rendering.WebAssemblyRenderer[100] Unhandled exception rendering component: The type initializer for 'DefaultProxyCache1' threw an exception. System.TypeInitializationException: The type initializer for 'DefaultProxyCache1' threw an exception. ---> System.ArgumentException: Invalid generic arguments Parameter name: typeArguments at (wrapper managed-to-native) System.Reflection.RuntimeMethodInfo.MakeGenericMethod_impl(System.Reflection.RuntimeMethodInfo,System.Type[]) at System.Reflection.RuntimeMethodInfo.MakeGenericMethod (System.Type[] methodInstantiation) <0x342def8 + 0x000d6> in :0 at ProtoBuf.Grpc.Internal.ContractOperation.TryGetClientHelper () [0x0001b] in //src/protobuf-net.Grpc/Internal/ContractOperation.cs:291 at ProtoBuf.Grpc.Internal.ProxyEmitter.EmitFactory[TService] (ProtoBuf.Grpc.Configuration.BinderConfiguration binderConfig) [0x00477] in //src/protobuf-net.Grpc/Internal/ProxyEmitter.cs:238 at ProtoBuf.Grpc.Internal.ProxyEmitter.CreateFactory[TService] (ProtoBuf.Grpc.Configuration.BinderConfiguration binderConfig) [0x0006d] in //src/protobuf-net.Grpc/Internal/ProxyEmitter.cs:123 at ProtoBuf.Grpc.Configuration.ClientFactory+DefaultProxyCache`1[TService]..cctor () [0x00000] in //src/protobuf-net.Grpc/Configuration/ClientFactory.cs:81

My project uses gRPC-Web, Blazor web assembly and protobuf-net

This is my service contract:

[ServiceContract(Name = "Services.Customer")]
public interface ICustomerService
{       
    ValueTask<Customer> CreateCustomer(Customer customerDTO);

    ValueTask<CustomerResultSet> GetCustomers();
}

The implementation is:

public class CustomerService : ICustomerService
{
    private readonly CustomerUseCases customerLogic;

    public CustomerService(CustomerUseCases customerLogic)
    {
        this.customerLogic = customerLogic;
    }

    public async ValueTask<Customer> CreateCustomer(Customer customerDTO)
    {
        var result = await customerLogic.CreateCustomer(customerDTO);
      
        return customerDTO;
    }

    public async ValueTask<CustomerResultSet> GetCustomers()
    {
        CustomerResultSet result = new CustomerResultSet { Customers = await customerLogic.GetCustomer() };
        return result;
    }
}

As for the Datacontracts:

[DataContract]
public class CustomerResultSet
{
    [DataMember(Order = 1)]
    public IEnumerable<Customer> Customers { get; set; }
}

And,

[DataContract]
public partial class Customer
{   
    [DataMember(Order = 1)]        
    public int CustomerId { get; set; }
    [DataMember(Order = 2)]        
    public string CustomerName { get; set; }
}

Before I was returning a List of customers in the service but I realize I needed a class to model the message in order to protobuf-net be able to serialize that is why CustomerResultSet. Still, it is not working. Any help much appreciated