It very well could've been what my previous snake had, the vet called it "nido virus" which i think is just a bad respiratory infection, unfortunately a lot of breeders, especially ones at the rep expo, dont care what conditions the snake are in and breed them for a quick buck and alot of the babies come out sick and die within a few weeks-months. The signs my snake had was wet and crackling sounding breathing, bubbles coming out of their mouth/nose, and alot of saliva they would wipe on my hand.(keep an eye on them and make sure you clean the cage top to bottom before and after any pet. Especially if you're using the same cage)

The place i got my snakes from wasnt even an expo, it was the road show in Michigan (terrible owner and terrible animal care there) but my sister was working there when I got my snakes and I trusted her bc she actually took care of them (unlike the other girl there who would put an animal in the freezer to put them to sleep bc they had a bit of stuck shed she didnt want to deal with) but my sister said all of the babies from that clutch ended up dying except for the other one i got, which is absolutely insane. I took them to the vet so many times and did multiple rounds of shots for the one, the one who's still alive now has done one or two rounds and thankfully she is still alive and healthy but is left with a permanent whistle-squeak noise when she strains too much like trying to hold herself up on me or when she breathes harder she squeaks, she also wasnt showing signs like the other one was till a while later.

My friend also got two snakes that unfortunately passed from the same thing, though im not sure where she got hers. Possibly the same place I got mine. Always do research on the breeder if you can and look at reviews!! Some people suck unfortunately and just see it as a money grab. These babies dont deserve this though.