Commerce Search Refinement doesn't work with picklist fields

Hi,
I am implementing commerce search using Connect API
[Rest Connect API](https://developer.salesforce.com/docs/atlas.en-us.chatterapi.meta/chatterapi/connect_resources_commerce_webstore_product_search.htm)
[Apex Connect API](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_ConnectAPI_CommerceSearch_static_methods.htm#apex_ConnectAPI_CommerceSearch_productSearch_1)
Unfortunately I cannot filter search results by picklist field value.
B2B Commerce on Lightning Doc states that picklist type is supported.

This is a sample of my code:

`

CommerceSearchDomain.SearchProductsWrapper searchProductsWrapper = new CommerceSearchDomain.SearchProductsWrapper();

searchProductsWrapper.webstoreId = input.webstoreId;

searchProductsWrapper.productSearchInput = new ConnectApi.ProductSearchInput();

searchProductsWrapper.productSearchInput.pageSize = APP_CommerceCatalogAPI.DEFAULT_SEARCH_PRODUCTS_SIZE;

searchProductsWrapper.productSearchInput.page = input.pageNumber;

searchProductsWrapper.productSearchInput.searchTerm = input.searchTerm;

ConnectApi.DistinctValueRefinementInput refinementInput = new ConnectApi.DistinctValueRefinementInput();

refinementInput.values = new List{'HE'};

refinementInput.nameOrId = 'Orders_3__c';

refinementInput.type = ConnectApi.CommerceSearchFacetType.DistinctValue;

refinementInput.attributeType = ConnectApi.CommerceSearchAttributeType.Custom;

searchProductsWrapper.productSearchInput.refinements = new List{refinementInput};
`

Picklist field values:

Running SOQL as B2B user returns Product records with correct value in specified field.
But commerce search returns an empty response whenever I try to specify value in Refinement. For empty refinements list it returns every record (accessible by user).

I tried to check other fields and using Checkbox field gives proper results from the Webstore Search.

Before using fields as search filters I configure commerce setup and rebuild search index

Any ideas what is missing in my code or configuration? Anyone had this issue before?