Bluetooth can be a useful technology for short-range connections, sometimes known as personal area networks (PANs). We use Bluetooth for fitness bands, earbuds and headphones, hotspot tethering, and input peripherals.
But sometimes your Mac seems to get the wrong idea about one or more devices. Even after unpairing and re-pairing, you can’t make a connection. Or, worse, macOS won’t let you remove a paired device from the Bluetooth preference pane.
Read more at Macworld.com