Can't apply audio fx preset on stereo track since 15.0

Since the 15.0 Update I am not able to apply my old audio fx presets on stereo tracks, which wasn't a problem in 14.9.

For example I saved a simple -18db volume preset and can only apply it on a mono track but not on a stereo music track. The track is set to "Clip Keyframes". And I figured out if you apply the -18db preset on a mono track the volume of the track is still 0db. I don't get it, 

Is this a bug? Can anybody help me? Thx!