Cannot programmatically retrieve language processing rules with Studio 2022 API from GroupShare Serever

I am trying to list the Language Processing Rules on a GroupShare 2020 SR1 Cu12 server using the Studio 2022 API.

I am applying the following method:

 translationServer.GetLanguageResourcesTemplates(false);

However, it returns a 400 bad request error, regardless of the parameter true/false. I can retrieve all other items such as TMs, Containers, field templates, etc. However, not language processing rules.

System.AggregateException: "At least one error has occurred."
Internal exception
HttpRequestException: The response status code does not indicate success: 400 (Bad Request).

Any idea what the problem can be?