Hi Kevin - thank you. I actually discovered this myself before seeing your response and came here to reply to my own post with the solution. As you correctly called out, the MAC address is listed on the bulb itself next to the label S/N which typically means serial number but which is being used as the label for the bulb’s MAC address. That threw me off at first until I recognized the format.
I downloaded a free network discovery app on Android (NetX by Netgel), connected and scanned the same WiFi network as the bulb, and then searched for the MAC address which then lists the IP address alongside it.
I used this IP address to configure my Google Home Assistant YAML configuration file which then finally rendered the bulb on the Home Assistant’s UI Dashboard. I don’t know why Windows 10 NetDisco service used by HomeAssistant is unable to detect any of my Lifx bulbs. They detect my Wemo Switches, my Chromecasts, Google Home, and many other devices automatically, but I have to manually add the Lifx Bulb IP addresses for them to be recognized.