They aren't counting the people who are being treated but haven't yet tested positive. For example, an organization that I am familiar with is reporting a small number of confirmed Covid cases, but has others being treated that are very likely COVID, but haven't had test results returned yet because they didn't meet requirements. The test takes longer if you don't meet the criteria. Goes to a different lab. That lab's turnaround has been getting shorter, but it's still significantly longer than the state lab where tests are sent if you meet the criteria.
So, we likely have more cases in hospitals being treated, but just no positive test yet