CoreBluetooth is disconnecting from unused peripherals due to an API Misuse

I am trying to connect to a MacBook Pro from an iPad with CoreBluetooth.

Here is my delegation for CBCentralManagerDelegate:

extension MasterViewController: CBCentralManagerDelegate {
    func centralManagerDidUpdateState(_ central: CBCentralManager) {
        if central.state == .poweredOn {
            print("Scanning for peripherals")
            central.scanForPeripherals(withServices: nil, options: nil)
            Timer.scheduledTimer(timeInterval: 3, target: self, selector: #selector(self.stopScan), userInfo: nil, repeats: true)
        }
    }

    func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
        print("Did discover peripheral", peripheral)

        central.connect(peripheral, options: nil)

    }

    func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) {
        print("Did connect to ", peripheral)

        peripheral.delegate = self
        self.remotePeripheral.append(peripheral)
    }

    func centralManager(_ central: CBCentralManager, didDisconnectPeripheral peripheral: CBPeripheral, error: Error?) {}
}

But when I scan I get this error in the log:

<Error>: [CoreBluetooth] API MISUSE: Cancelling connection for unused peripheral

Why does this happen?

Not sure why this worked, but I found that it works if I assign the peripherals delegate to self, and add the peripheral to an array before I connect to it.

func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
    print("Did discover peripheral", peripheral)

    peripheral.delegate = self
    self.remotePeripheral.append(peripheral)

    central.connect(peripheral, options: nil)

}