Regarding the missed fasting due to ignorance of reaching puberty:
1) He is not required to make up for the fasts missed during the time he was unaware of his maturity, as he was not accountable for his actions during that period.
2) There is no penalty for delaying the fasts since he was not aware of the obligation to fast.
Source: Islamic Q&A.
Regarding the missed fasting due to ignorance of reaching puberty:
It is important to note that he is not required to make up for the fasts missed during the time he was unaware of his maturity, as he was not accountable for his actions during that period.
Source: Sistani's Islamic Q&A.
May Allah guide us all.