How do I get and apply the ambient light estimate values from the hololens 2 to a DirectionalLight

So far i tried to get the light estimate values by calling GetCurrentLightEstimate, which should return a UARLightEstimate. I should be able to cast it to a derived type according to my session config, which is UARBasicLightEstimate. The UARBasicLightEstimate object holds the information that would be applied on the directional light.

The problem is that GetCurrentLightEstimate returns null and I do not know why.