I am investigating the aging issue, but examining the code reveals no particular reason why this happens, other than perhaps your game having a backlog of aging that it was slowly working through before you turned it on. The cutoff seems quite clear, unless something is now suddenly managing to bypass it. Can you directly observe the aging? Does it happen with only specific ages, such as elders dying, or is it acting as if the setting is being ignored?
So far has aged babies to toddlers, toddlers to children and children to teenagers..