I don't have enough experience to comment to much, but I can share a story about my snakes that may shed some light, although it's just my hypothesis right now. I have seven balls, all but one are very nice tempered snakes when I keep them in my rack. I keep one snake in a glass front cage when she spends time at work with me. Any of the snakes that have been in that cage are way more cage aggressive. I always suspected it was due to the reflection on the glass. As so as they are out they are instantly puppy dog tame. If they are out back into the rack that cage aggression is gone. Could it be reflections on the glass spooking your snake a bit?