Polygon market snapshot content nothing but "OK"?

Alpaca Market Data
1

Last night, in response to:

curl "https://api.polygon.io/v2/snapshot/locale/us/markets/stocks/tickers?apiKey=yada yada"

I keep getting:

{"count":0,"status":"OK","tickers":[]}

This, after the initial invocation of that same curl command returned the expected snapshot JSON.

Is this expected behavior for some reason?

Note: I haven’t used this account (apiKey) in a year, so that may have something to do with it.