UB400 adapter won't connect to any device
I just bought the UB400 bluetooth adapter off Amazon (actually came in a pack of two). Plugged in to my Windows 10 desktop and the adapter is instantly recognized. The problem is that I can't connect to any of my devices (phones or tablets). I can actually pair the adapter to either phone or tablet, but it "fails to connect" so I'm unable to use it.
Looking in Windows, everything seems to be set up just fine. It shows in device manager, and in control panel Devices and Printers. My other devices see it, and it sees my other devices. It just won't connect. Any thoughts on how to solve this?