You are seeing the iPad’s hardware (MAC) address - this being a globally unique identifier associated with the WiFi, Bluetooth or wired network connection.
You can find all the WiFi & Bluetooth interface MAC addresses listed in your iPad (and iPhone) settings:
Settings > General > About
If you have iOS/iPadOS15.x installed, you may be using Apple’s Private Addressing feature - this being intended to hide the “real” MAC address (remember, this is globally unique - and may be used to identify your specific device). With Private Addressing enabled, a “pretend” MAC address is generated, thus hiding the real address from the network to which you are connecting.
Private Addressing is enabled/disabled for each WiFi network to which you connect:
Settings > WiFi > [WiFi Network Name / SSID] - tap the blue “i” icon - Private WiFi Address - set to ON or OFF as required
Each time this feature is re-enabled, the visible MAC address will change.