Discovered unknown cell phone logging in

My computer has been running very slow. I am not 100% sure what this software is. However, I downloaded it to further investigate. I am running a home PC Win 10 x64. An Xbox and daughters laptop are 'on the network'. I keep getting dialogue box notifications that a cellphone is logging "in". They pop up quick then go away, I do not know where to find them. My cell phone is in my pocket, it is not logged on. My daughter is at work. We do not use mobile phones on the network, that would make no sense - we have unlimited. Possibly she accidentally clicked something. However, how do I figure out exactly what is going on.

I see 10 "devices" listed in the SoftPerfect network scanner. The host names are not too specific. One is clearly my modem/router, I suppose. Not really sure what the others are. Program seems pretty good. Hopefully this teaches me to use it as well. I am looking at the manual. It is just a lot to process at the moment. Any quick tips or advice. These phones are most likely not ours. (This phone?)

The Network Scanner application is intended for network administrators and is quite sophisticated.
For a novice or a home user it is better to try something simpler. If your aim is only to discover devices in your network, you may like to try WiFi Guard, or a basic app from another developer.