New Phone - Adding duplicate Presence Sensors?

Just got new phones. Installed and logged into the app, and set up Geoloation. Went to devices so I could name them, and realized there were two instances each time I added the phones.

One that actually had a "Current State" and one that did not for each one. Testing the device notification feature, the one that had a current state worked, and the other did not. All four devices have unique DNI's which I obscured.

So, I deleted them all, deleted cache and data in the app, and then went through the process individually. Added one phone, went to devices, and there were 2 instances again. I labeled the phone with a good "current state" as the phone device I am using. The other, I labeled with initials and unknown. Then, I did the other phone.

So, after a day, the ones that I thought would work are working fine (actually appear to be more responsive than the old phones) and the "unknown" shows that the last activity was the time of creation.

Now getting to my questions:
1- I should be good to delete the ones that are not updating ("unknown"), correct?

2- Any idea why this would be creating duplicates when going through the add device? I kow this did not happen with my original phones.

3- Lastly, unrelated, but does anyone know if the device notifications require internet if you are on local wifi? (Just curious on this as I had asked about it in another post, but the question was misread). So, the scenario is, for some reason, cable goes out, but I have power and the local network is humming along fine. If a notification is sent to the phone on the local wifi, will I get it? Or does that require WAN?

Duplicate Devices