Hardware mac address clone?

[baboeska]

Hi,
I went on holiday, and when I came back, 3/4 of my ESP32 Camera boards had identical mac addresses, resulting in major issues being able to use them for surveillance.
In theory this isn't possible, however, it happened, without a doubt.
Clearly there is a means for burglars to rewrite ESP32 hardware level addresses, is my current hypothesis.
I hope to hear others, and perhaps, how to fix it so they have differing mac addresses again?

Thank you for your time,

[Sprite]

How do you conclude they have the same MAC address? Also what firmware are you running?