They are likely BLE (Bluetooth Low Energy) devices, which you're really not connected to. Bluetooth is constantly scanning for devices to pair with. Only BLE devices may show as connected, but aren't. They could also be associated with an app you have for some device, which connects with the app and shows in your Bluetooth list. Most of these are fully explainable and not usually cause for concern. If I go for a walk around my neighborhood, I'll often see that an Amazon Echo is connected, which isn't mine. They are BLE devices and not something I'm concerned with as I'm not actually connected to them.
Unless they are listed under My Devices, with a circle with an i in it, you're not actually connected to them.