Sophos Central Partner API - tenants billingType always null

Hi,

I have a question about the Partner API GET tenants method described here
https://developer.sophos.com/docs/partner-v1/1/routes/tenants/get

Starting from januari 10th this year, the billingType attribute always returns null.

GET https://api.central.sophos.com/partner/v1/tenants?page=1&pageSize=50 
with X-Partner-ID header set to a uuid returns

{
    "items": [
        {
            "id""removed",
            "name""removed",
            "dataGeography""IE",
            "dataRegion""eu01",
            "billingType": null,
            "partner": {
                "id""removed"
            },
            "organization"null,
            "apiHost""">api-eu01.central.sophos.com"
        },
...



Earlier it used to return : term, trial, usage.

Why has this changed?