The action=query&prop=description API doesn't provide description nor descriptionsource fields in the Wikipedia beta cluster anymore. (It still works in production at this time.)

Steps to Reproduce:
https://en.wikipedia.beta.wmflabs.org/w/api.php?action=query&prop=description&titles=San%20Francisco

Actual Results:
Output does not include description nor descriptionsource fields.

{
    "batchcomplete": "",
    "query": {
        "pages": {
            "5680": {
                "pageid": 5680,
                "ns": 0,
                "title": "San Francisco"
            }
        }
    }
}

Expected Results:
Output includes description nor descriptionsource fields.
Should be similar to production (but different page id, of course). It should be something like:

    "batchcomplete": "",
    "query": {
        "pages": {
            "5680": {
                "pageid": 5680,
                "ns": 0,
                "title": "San Francisco",
                "description": "City in the USA",
                "descriptionsource": "central"
            }
        }
    }
}

Checks done so far:

• This Wikipedia page does not have a local short description.
• https://wikidata.beta.wmflabs.org/wiki/Q500978 does have a description and the Wikidata API returns it.
• See P11087 showing null returned for $termLookup->getDescription($itemId, 'en'). Maybe some kind of cache corruption or a bug in Wikibase extension?
• Also tried a few other pages on the WP beta cluster. All missing the description.

[1] https://github.com/wikimedia/mediawiki-extensions-Wikibase/blob/master/client/includes/Api/Description.php