Unknown device appeared on Eero network with hostname of a mobile device, unauthorised access?

[UberTiger]

I have a Dream Machine Pro setup at a family members home, it has a few eeros hooked into it temporarily until I add some UniFi access points. It works fine and was plug and play swapping the old router out, so I wasn't too fussed as everything stayed connected.

It's been setup for weeks, in the last hour I got an unknown private device eero notification to my phone. Looking up the mac address online shows nothing, but the hostname for the device in eero app says "SomeName-S23-Ultra"

This sounds like an Android Samsung S23? Eero app says 0kb uploaded or downloaded.

Would it be right that the hostname for a Samsung mobile would be labelled in this way?
Does this mean someone has gained unauthorised access to my network?

 

[UberTiger]

Edit: I've now blocked the device completely, there's not really anyone to shout or not beside the immediate family member, which is a bit concerning.

I don't want to alarm them tonight if I don't have to, and I'm pretty sure there's no 'SomeName', visiting the house, but I'll check with them tomorrow.

It's such a rare occurrence getting an new device eero ping, I'm a tad worried. Might be time to rotate the wifi password (which is reasonably strong, but has been the same for a while)