App review algo change?

Did the app review algorithm change in the last day or so? I’ve been at 5 stars for a long time now, and suddenly it dropped to 4.9 stars. I believe previously it was pulling recent reviews so if I had a lower review, that would change my average. But all my reviews in the last 2.5 years have been 5 stars. So I’m confused as to why my average would drop now.