language_tag

Describe the bug

I'm trying to create a BookingBusiness with a language_tag "nl-BE" or "fr-FR". But none of these values actually persist when doing the post call.
It defaults to en-US

Expected behavior

I want to set the language for the reservation page to "nl-BE".

How to reproduce

request_body = BookingBusiness(
    display_name = f"xxxxx",
    email = "x@x.com,
    business_type = "xxxxx",
    default_currency_iso = "EUR",
    language_tag="nl-BE",
    address=PhysicalAddress(
        street="xxx",
        city="xxxxx x",
        state="xxxxx",
        country_or_region="xxxx",
        postal_code="xxxx"
    ),
    booking_page_settings = BookingPageSettings(
        business_time_zone="Europe/Berlin",
        is_time_slot_time_zone_set_to_business_time_zone=True,
    )
    
)
await graph_client.solutions.booking_businesses.post(request_body)

SDK Version

1.12.0

Latest version known to work for scenario above?

No response

Known Workarounds

No response

Debug output

</details>


### Configuration

 OS: MAC OS 15

### Other information

_No response_

Start with the BookingBusiness model and the POST serialization path used by graph_client.solutions.booking_businesses.post. Reproduce the request with language_tag set to "nl-BE" and inspect the serialized payload and response. Done means the requested language tag is sent and is retained instead of defaulting to "en-US".