BUG: Type mapper not calling first output ref

[IceBlizz6]

I believe i may have found an issue with type mappers.
I created a reproduction below.

public class DummyTypeMapper implements TypeMapper {
    @Override
    public GraphQLOutputType toGraphQLType(AnnotatedType javaType, Set<Class<? extends TypeMapper>> mappersToSkip, TypeMappingEnvironment env) {
        mappersToSkip.add(this.getClass());
        GraphQLOutputType resolvedType = env.operationMapper.toGraphQLType(javaType, mappersToSkip, env);
        System.out.println("Output: " + resolvedType);
        return resolvedType;
    }

    @Override
    public GraphQLInputType toGraphQLInputType(AnnotatedType javaType, Set<Class<? extends TypeMapper>> mappersToSkip, TypeMappingEnvironment env) {
        mappersToSkip.add(this.getClass());
        GraphQLInputType resolvedType = env.operationMapper.toGraphQLInputType(javaType, mappersToSkip, env);
        System.out.println("Input: " + resolvedType);
        return resolvedType;
    }

    @Override
    public boolean supports(AnnotatedElement element, AnnotatedType type) {
        return true;
    }
}

public class SearchService {
    @GraphQLQuery
    public String search1(String key) {
        throw new Error();
    }

    @GraphQLQuery
    public String search2(String key) {
        throw new Error();
    }
}

GraphQLSchema schema = new GraphQLSchemaGenerator()
                .withOperationsFromSingleton(new SearchService())
                .withTypeMappers(new DummyTypeMapper())
                .generate();

The output here will be:

Output: GraphQLScalarType{name='String', .....
Input: GraphQLTypeReference{name='String'}
Output: GraphQLTypeReference{name='String'}
Input: GraphQLTypeReference{name='String'}

Service defines 2 operations where both return string and inputs a string.
So there are 4 type references here, but mapper only picks up 3.
It seems like 1 output reference is always skipped.

Similarly if we try this with only 1 operation:

Output: GraphQLScalarType{name='String', ...
Input: GraphQLTypeReference{name='String'}

(no type output references are called)