Source 4 Bench Focus Issue

I've just finished cleaning a handful of our 26 and 36 degree units. I had to take the barrels apart to clean the lenses as there was a visible layer of residue on most of them. I did this one by one, following the instructions in the assembly manual. Now as I'm bench focusing them, I notice that I can see the lens pads in the beam image on many of them when I run the barrel in or out. I double checked several of them as I was focusing and made sure the lenses were are seated properly in the correct slots and facing the right direction. I compressed the lens cap all the way in before I started on each light, but I'm still seeing this aberration. I've added an image from a 36 degree fixture mid bench focus. You can just see the outline of the lens pads around the edge of the beam. Does anybody have any ideas or suggestions on how to fix it?