I think everyone else has already got some good points in.
I definitely agree that 44g is way too small for a sale. My 2nd clutch hatched out at mid 50s and one runt at 27g. I sold the first hatchling off at 2 months and 97 grams after 5 meals.
My runt just hit 58g and she's finally eaten 3 meals by herself. They all hatched on July 8th.
Personally I don't know how your baby even found food in the enclosure if a snake that small was in a 40gallon. Even a 20 can be way too large for a snake of this size. Especially now with the stress of over handling and the vet treatments, you may need to go back to basics and try a simple plastic tub setup. They sometimes feel way more safe and secure in a smaller space and that gets them to eating. As Boger mentioned though, most snakes on medicine won't eat in my experience.
Otherwise, 2 hides in a 20l is definitely not enough. You either need to add extra fake plants and foliage for cover or extra hides. They like the clutter. The baby will feel safer and may start to turn around once finally able to ambush hunt.
I hope your little one pulls through. Thank you for getting them to a qualified vet as soon as you did.