Advice needed - merging two schemas does not work as expected

[kfrajtak]

Hi,
I am trying to merge two schema in one following this example but keep getting this error:

The name `IntOperationFilterInput` was already registered by another type. (HotChocolate.Data.IntOperationFilterInputType).

TypeModule dynamically creates types from database a Query is as follows:

[ExtendObjectType("Query")]
public class Query
{
  [GraphQLName("objectSets")]
  [UseFiltering(typeof(ObjectSetFilterType))]
  public IEnumerable<ObjectSet> GetObjectSets([Service] EasyIDMDbContext context) => context.ObjectSets.ToList();
}

public class ObjectSetFilterType : FilterInputType<ObjectSet>
{
  protected override void Configure(IFilterInputTypeDescriptor<ObjectSet> descriptor)
  {
    // descriptor.BindFieldsExplicitly(); 
    // causes The object type `FilterDefinition` has to at least define one field in order to be valid
    descriptor.AllowAnd(false).AllowOr(false);
    descriptor.Field(f => f.IdmObjectTypeId); // single field filtering is intended
  }
}

Configuration

var builder = services
  .AddGraphQLServer()
  .AddTypeModule<TypeModule>()
  .AddTypeExtension<Controllers.Query>()
  .AddFiltering<Data.GraphQL.Filters.Conventions.FilterConvention>()
  .AddSorting(c => c.AddSortingDefaults());

When I remove the UseFiltering attribute, I get different error:

1. The object type `FilterDefinition` has to at least define one field in order to be valid. 
(HotChocolate.Types.ObjectType<EasyIDM.Model.Filtering.FilterDefinition>)
  HotChocolate.SchemaException: For more details look at the `Errors` property.

The FilterConvention is pretty standard

public class FilterConvention : HotChocolate.Data.Filters.FilterConvention
{
    protected override FilterConventionDefinition CreateDefinition(IConventionContext context)
    {
        return base.CreateDefinition(context);
    }

    protected override void Complete(IConventionContext context)
    {
        base.Complete(context);
    }

    protected override void Configure(IFilterConventionDescriptor descriptor)
    {
        descriptor.BindDefaultTypes();
        descriptor.AddDefaultOperations();
        descriptor.Provider(new FilterProvider());           
    }
}

Questions are

1. how to tell HC to ignore previously registered type
2. how to functionally disable filtering on a type level

I guess I am missing something ...
Can you help me?
Thanks,
Karel