Question about something odd Ive never seen

I've been keeping balls since '02 (still have my first hatchling I got when I was in the Marine Corps who is still thriving) but I expirenced something strange this year. I produced a clutch of 8 hatclings all who are doing well except one. He is a male pastel that I was going to give away as a pet. He hatched out on Aug 3 and everything appeared normal with him. He was a bit of a trouble eater but I got him to eat 4 rat pinkies over the last 2 months, but he was consistently losing weight even though he was eating small meals. Today when I was cleaning I found him dead. He only weighed 35 grams but the other hatchlings from his clutch are between 85-100 grams now. My question is has anyone ever experienced any thing like this where a hatchling does eat but does not gain weight. I understand a necropsy is the only way to determine how he died, I just found it strange he ate 4 times in 2 months and never gained weight. Any experiences or input would be appreciated.

Sorry about the double post I forgot no apostrophes

There are a whole host of reasons why a hatchling (or any animal) can eat but still not gain weight or survive from metabolic disorders to a faulty digestive track. As you already said, without a necropsy (and probably even then) there is no way to guess what happened.

The general term for such occurrences is 'failure to thrive'.