(Chroma SDK) QueryDevice doesn't find connected devices

I hope this is the right place to post my question.

I own a Blackwidow V3 Mini Hyperspeed and a Naga X.

I've played a bit around with the Chroma SDK. Everything basic works as expected, i.e. I can create predefined and custom effects on both devices. But QueryDevice() gives me some headache. No matter what I try, i can't detect if any of my devices are connected.

I tried all GUIDs in "RzChromaSDKDefines.h":
The return value of QueryDevice() is always 1167 (RZRESULT_DEVICE_NOT_CONNECTED).
The DeviceType field of DeviceInfo has the correct value.
The Connected field of DeviceInfo is always Null...

Am I missing something? Could it really be possible, that both of my devices are not fully implemented yet?