Ah ok, that was my only idea 🙂
The reason for disabling the private address option is that otherwise the phones generate fake MAC addresses each time they come across a network (to thwart easy tracking of devices across public networks) which could cause a router to get full up of what it thinks are a continual stream of new devices.
I don’t know if Android has a similar feature - usually, iOS just copies Android so you might have it 🙂 Anyway, check in the router admin pages and see how many devices it has attached, and also while there you can check the logs.
In the Connect Box admin page, they’ve kind of hidden it …
Advanced Settings / Tools / Network Status / Networklog