Ambient Zone "Exterior LPF" not working ?

Hello,

I’ve made a really simple test level with one AudioVolume and one AmbientSound which is outside the AudioVolume.
I also made my own SoundClass with “ApplyAmbientVolumes” enabled and assigned my AmbientSound to it.

When I set ExteriorVolume to 0.1 in the AmbientZone settings of the AudioVolume it works as intended: As soon as the Player enters the Zone the AmbientSound is faded to 0.1 Volume.

When I set ExteriorLPF to 0.1 or even lower there is no effect at all when entering the Volume.

I tried to use the LPF Attenuation on the AmbientSound to make sure LPF can affect my sound and that one also works as intended: If the Player walks away from the AmbientSound the Filter closes with increasing distance.
So LPF depending on distance works and the only thing that isn’t working is the LPF when entering AudioVolumes.

Did anyone manage to get this feature working yet?

I’m struggling to here the effect of the LPF in audio volume settings also. I cannot seem to get it to effect the audio as i think it should be doing. Is this a bug or are we missing something?