GetActiveFusionProvider returns 0

Using Unity 2018.3.0f2 and Vuforia 8.0.10

I want to check if my Huawei Mate 20 Pro is using ARCore with this line:

Debug.Log(VuforiaRuntimeUtilities.GetActiveFusionProvider());

But the output is 0. What does that mean? According to the docs it should never return 0.