I don’t think you’ve found a “glitch” because every time I created a world in Minecraft on the X360 version it’d spawn a new beginning chest, after I had taken everything the first time. I could be wrong, but I remember gathering a ton of chests from doing so.
It’s not a bug, it’s just the map is set to always spawn a chest when it’s booted up. They aren’t excellent spawns but it does help for free chests and torches I must admit. Been doing this for a long time now.