Apple Watch MAC address doesn't match IP Scanner report

This isn't an urgent issue in any respect; I'm just curious. I have an Apple Watch Series 6 that is connected to my WiFi network. Whenever I use IP Scanner to assess my network, it reports about 18 devices, e.g. HomePods, iPhones, routers, A/V receiver, iPads, BlueRay player, etc., etc. There is one item that always shows up as "unidentified device" with an unknown manufacturer. My Apple Watch does not appear in IP Scanner's list but is, indeed, connected to and functioning on my network. The curious thing is that the MAC addess in IP Scanner does not match the address reported by the watch. I have attached a screenshot from the watch and two from IP Scanner to confirm that fact.

Can anyone explain the discrepancy?