QBluetoothDeviceDiscoveryAgent BLE scan only finds previously known devices

When scanning for nearby BLE devices, QBluetoothDeviceDiscoveryAgent finds only previously known devices. "hcitool lescan" is able to detect my device reliably every time. And gatttool is able to connect and read/write data.

Often, after hcitool finds the device, a subsequent run of my Qt application, QBluetoothDeviceDiscoveryAgent also finds the device. But this is not predictable.

I have called start() with QBluetoothDeviceDiscoveryAgent::LowEnergyMethod. I tried both without setting any value for setLowEnergyDiscoveryTimeout() and with 30 seconds timeout and restarting the scan on finished().