TR-064 | Fritzbox 7590 - Device Mac Address stays online

Hi,
I have a new issue.
My wife got a new iPhone 16 Pro (iOS 18) and ever since upgrading to the new iPhone, the corresponding mac address stays online according to the TR-064 binding.
My Pixel 7 Pro works flawlessly.
I’m using OH 4.3
AVM FritzOS 8.00

This is quite frustrating, as I use a combination of pingable IP address and online mac address to determine the presence state.
It worked perfectly with her old phone (iPhone 12 mini - iOS 18).

All I changed in the bindings config is the mac address (to her new phone’s mac address).
Any idea what I can do ?

My analysis:

My wife was with me (out) all the time, but her analysis looks like this:

As you can see - something’s wrong

Any help would be great, thanks !

Edit - 28.12.2024:
Interesting fact, I rebooted our fritzbox and switching off the iPhone’s WiFi was registered almost instantly by the TR-064 binding.
Will keep an eye on this…