Apple - iPhone reports 2 Hotspot connections even though only one of my devices is connected

Other devices (including iPads, iPods, Macs, and other iPhones) connected to the same iCloud account as your iPhone will, if in WiFi range, automatically connect to your iPhone's hotspot when it's turned on (according to this Apple Support page and my personal experience). That means if any of your other devices are lying around, they will automatically connect to your iPhone's hotspot using iCloud.

tl;dr: Other devices tied to the same iCloud account might automatically be joining your iPhone's hotspot network.

I came here because I saw a 3 connections to my iPhone hotspot. But then checked if just because I was charging through my laptop. The USB is the 3rd Connection, which disappears as soon as I unplug.