I never changed a MAC address and also I wouldn’t know how to do this. The two clients are a Volla phone and another Xperia 10, while the first Xperia 10 from which I tell ist my general internet access for everything in the house, with VPN, and nothing else installed on it.
A Volla and a Xperia 10 should IMHO have different MAC addresses.
Also I checked right now in settings/product information and found different MAC addresses.
Volla begins with 58:9e…
Xperia 10 begins with 38.78…