I have some .net tooling for my embedded devices. I am performing a systems update on them at the moment and would like to start using extended advertising for the payload size increase. I have a TP-Link UB500 dongle that I use from my windows11 machine to fascilitate the tooling. I have just updated to the latest driver version from the tp link website and it is now showing up as a 5.3 adapter. Here’s where the problems start.

I am using the BluetoothLEAdvertisementWatcher object from Windows.Devices.Bluetooth.Advertisement. This works for my legacy project but when I set AllowExtendedAdvertisements to true I do not see my extended advertisement device. I am using a nrf52840 ble sniffer in wireshark to confirm that the device is advertising. I set up a little hook in the receiver to tell if I ever see my device, but I don’t.

watcher.Received += (BluetoothLEAdvertisementWatcher watcher, BluetoothLEAdvertisementReceivedEventArgs eventArgs) =>
{
    if (eventArgs.AdvertisementType == BluetoothLEAdvertisementType.Extended || (eventArgs.BluetoothAddress == targetAddress))
    {
        Console.WriteLine("Found extended packet?");
    }
}

In device manager under Properties>details>”Bluetooth radio supports Advertising Extensions” the option is false. Additionally when I run the following it shows as false.

var ba = await BluetoothAdapter.GetDefaultAsync();
Console.WriteLine(ba.IsExtendedAdvertisingSupported);

So is there some windows options to enable this feature given that the driver indicates the adapter is 5.3 which surely supports this feature by now? Am I misunderstanding the usages of
AllowExtendedAdvertisements?