> I wouldn't even know how to set up a "Private Wi-Fi Address", and I'm the most computer savvy here.
Follow the instructions in my post:
Settings -> WiFi -> <network info> -> Private WiFi Address and toggle the switch. Apple really couldn't have made it easier. You don't need to be tech savvy to turn it on/off, although understanding how it works/what it does requires a little more understanding.
The Private WiFi address uses a private class MAC address that wouldn't be associated with any vendor and seems to match your situation.
In either case, check the settings. It will tell you what private MAC address it's using and see if it matches the device you're looking for.