QBluetoothDeviceDiscoveryAgent can not find already connected BLE devices

I ran QT ble scanner example on Mac mini and I had two ble HID devices(a ble mouse, a hid development board) already connected to the system, but the ble scanner could not find them.

When I disconnected the hid device from system, the scanner could discovery the device and show its name.

I can use QBluetoothLocalDevice::connectedDevices() to get the bluetooth address, but it seems there is no way to get the device info when it is connected.