I guess he could have changed places. With his parents, most probably. And not few times. I mean, I did, and we kind of had a steady income more often than not. I always stayed in the same neighbourhood, but easily could've not. And as a street kid, I guess he would wonder even more.
It probably is a soft retcon, though.
It’s also possible that he grew up in crime alley but spent a lot of time in the Hill too.
The story doesn't have anything that implies Jason was born and raised on The Hill. Dana's dialogue makes clear Jason arrived at The Hill when he was already Bruce's ward, and that is precisely how he got enough money to buy a building of his own. This comes with its own slew of problems since Jason is still pretty much an outsider and depending on how you see it, it also aged him 12 years (making him 32 at least) for the timeline proposed to make sense.
Martinbrough was clearly wanting to write a story about The Hill and Jason was just a convenient excuse to do it, that's why Jason's characterization is pretty much something getting the cliff notes of his character from Wikipedia and why the whole setting feels like it was written with Dick in mind rather than Jason.
Well, Martinbrough did co-create The Hill, so I can see why he wants go back to his baby. Yeah it sucks but at least he's only on for two issues.
I honestly hope Jason moves back out of Gotham after this is done, actually. Unless they've found a new angle to approach Red Hood and Batman co-existing as the top dogs in Gotham, then it'll just be waste to have him spinning his wheels there.