Calculatedcftype searcher not working properly

I am creating a viewable, not editable custom field that extends CalculatedCFType API
However, the searcher that I’m implementing is not working properly.
The code that I have written seems to be bug-free, plus I have re-indexed the project.
Is this custom field searchable or it contains some limitations concerning the searchability?

The API doc (CalculatedCFType (Atlassian Jira - Server 9.0.0 API)) says:

Note that this used to implement SortableCustomField, but it is now up to subclasses to opt-in to sortable if they really want it. This is mostly not recommended because of the poor performance of using that interface - see NaturallyOrderedCustomFieldSearcher and SortableCustomFieldSearcher for the preferred approach to sortable Custom Fields.

So CalculatedCFType is no longer sortable. Your subclass can, but you will have to do it yourself.