Fader automation seemed to not work on a tight loop... loop removed, automation worked.

x2 prod
win 8
 
A loop of 1 second or so that included a slight click on a microphone I wanted to remove with fader automation.
 
I notched the envelope at the visible click with the loop playing, but it kept playing the click. Confused I notched more and more. Despite the fact that the gui fader bounced, I could still hear the click. I muted the solo'd track to ensure that nothing else was also solo'd and I got silence. I unmuted. I went to the but the track routes to and notched the volume on the bus the same way at the visible click in the wave form preview. I still hear the click. I'm totally puzzled. The faders visibly bounce up and down both on the bus and the track where I have it notched but the volume doesn't react.  I hit L to turn off the loop, back up in the project and play through and the click is gone - in other words the fader notch works to remove the click.
 
For even more amusement, I hit L again to turn the loop points back on and the click is back.... Sooo... does fader automation not work with a very short loop in X2? I expanded the loop to more than 2 seconds and I didn't hear the click. I contracted it back to 1 second and the click returned. I'm guessing that this behavior is repeatable.
 
Does fader automation need a certain period of time to start tracking? It seems no. If that were the case, I could position the NOW TIME 1 second before the click and hear the click, but this doesn't work. I can only repeat it within a loop.