Can't pair a third-party Bluetooth mouse with my old MacBook Air but can with my new MacBook Air
I can't pair a third-party Bluetooth accessory (mouse) with my old MacBook Air (os BigSur 11.1) but was able to do so with my new MacBook Air (os Ventura 13.0) even without the USB plug-in receiver provided. How is that so? Why is it working even without it?
And the other old MacBook can't find it but can see other devices, even my new MacBook?
MacBook Air 11″, macOS 11.1