After updating to iOS 13 on my iPad, the MAC address in Glasswire for that device does not match the address listed on the device. The IP address is correct though. The network monitoring app provided by my ISP shows the correct MAC and IP addresses. Any idea why this is happening and what I can do to update the MAC address to be correct?
This is a “feature” Apple made for you. It’s called Private Wi-Fi addresses.
You can switch it off in iOS settings if you tap the WiFi network name.