How do I disable these new device notifications?

And I'm okay with the notifications now that I understand what's happening. I thought I was going to be receiving notifications each time a device connected to my network, like if I left the house with my phone and came back, I would get a notification. But it appears I'm only getting notifications the first time a device connects to my network (i.e. when a device that has never connected connects). I'm assuming this was a result of me performing a factory reset on the router.