Hi,
For the rare things that I believe to know about iOS (please others confirm/disconfirm), if two iPhones scan the same peripheral, the two users will see different UUIDs. iOS generates the UUID for the device and hides its MAC address.
This has worsened yet: starting from iOS 11, even specialised apps can’t view MAC addresses any longer.
If this "feature" affects your business, or even your home network, please contact Apple: https://www.apple.com/feedback/
Sure this won't help... (but at least it's not me who have decided to implement this on our phones...)
PS: For your particular case, try to follow BobTheFisherman's advices.
Regards.