Your corn's name is fantastic

I work with dogs at a boarding and training facility (and have socialized many snakes and chameleons for people over the years), so I can happily tell you that barrier aggression (or "cage aggression" in your corn's case) is super common but it's also very easy to train out! Obviously training this behavior out of snakes is a bit more tricky than training it out of dogs (a shame they don't make snake training treats!), but I was able to turn my recently adopted (adult) rat snake from a striking terror to a docile thing in two weeks by:
1. I spent 10-15 minutes every couple of hours or so each day just sitting next to his enclosure, reading a book or something. I still do this. They like to watch you without you "noticing" them

2. Once he stopped rattling his tail and hissing at my presence I started opening the enclosure while I sat by him (without taking him out, I let him just chill in there and come out on his own).
3. My rat snake isn't used to being handled, so in order to keep him from being stressed out while training the barrier aggression out of him my next step was just to rest my hand in his enclosure, eventually petting him after he's had a chance to relax from my hand's sudden intrusion into his space.
4. Over the course of two weeks it's gotten to the point where the only thing he does when I pull him out is cling to me for dear life

He'll get better about being held/carried around once he gets used to it.
A lot of working out behavior problems is getting to know your pet to the point where you can accurately read their body language 100% of the time. It just comes with practice, consistency, and dedication!
I wish you the best of luck with your little guy~ I'm kind of bummed my rat snake doesn't hiss at me anymore

It was really adorable.