**Elastic.Clients.Elasticsearch version**: 8.19.0-preview.2 **Elasticsearch version**: 8.18.1 **.NET runtime version**: 8 **Operating system version**: **Description of the problem including expected versus actual behavior**: Before, the following code was working just fine. ```csharp BulkRequestDescriptor descriptor = new(); descriptor.Index(indexName); ``` Now, the same code does not set the index correctly. **Steps to reproduce**: **Expected behavior** **Provide `ConnectionSettings` (if relevant)**: **Provide `DebugInformation` (if relevant)**: